The Word of the Day first appeared in Sesame Street’s 38th season and was seen again in the 39th and the 40th seasons. The segment highlights a particular word introduced before the show with What's the Word on the Street? In the 39th season, the muppet characters, usually Elmo, would usually interupt the celebrities' conversation for something that has to do with the word.

Segments

Season 38

• Squid, with Brian Williams (First: Episode 4135)
• Newspaper, with Matt Lauer (First: Episode 4136)
• Dog, with Conan O'Brien (First: Episode 4137)
• Lazy, with Richard Belzer (First: Episode 4138)
• Pumpernickel, with Rachael Ray (First: Episode 4139)
• Ballet, with Ellen DeGeneres (First: Episode 4140)
• Tricycle, with Alec Baldwin (First: Episode 4141)
• Disappear, with Chris Brown (First: Episode 4142)
• Ticklish, with Howie Mandel (First: Episode 4143)
• Frustrated, with Kelly Ripa (First: Episode 4144)
• Prepared, with Chad Pennington (First: Episode 4145)
• Family, with Al Roker (First: Episode 4146)
• Mystery, with Mariska Hargitay (First: Episode 4147)
• Mail, with Christopher Meloni (First: Episode 4148)
• Predicament, with Charles Gibson (First: Episode 4149)
• Windy, with Gina (First: Episode 4150)
• Apology, with Ann Curry (First: Episode 4151)
• Gigantic, with Ahmad Rashād (First: Episode 4152)
• Rhyme, with Ice T (First: Episode 4153)
• Amazing, with Rachael Ray (First: Episode 4154)
• Expert, with Diane Sawyer (First: Episode 4155)
• Practice, with Jon Stewart (First: Episode 4156)
• Pretend, with Meredith Vieira (First: Episode 4157)
• Sigh, with Sarah Jessica Parker (First: Episode 4158)
• Angry, with Cuba Gooding, Jr. (First: Episode 4159)
• Struggle, with Tyra Banks (First: Episode 4160)

Season 39

• Octagon, with Jack Black who was stopped by Elmo (First: Episode 4161)
• Pirouette, with The Feijoo Ballerinas who were helped by Grover (First: Episode 4162)
• Laundromat (originally with Leela, but not shown due to more segments) (First: Episode 4163)
• Compliment, with Heidi Klum who was helped by Elmo (First: Episode 4164)
• Insect, with Jenny McCarthy who was helped by a bee (First: Episode 4165)
• Subtraction (song shown for more segments) (First: Episode 4166)
• Toss, with Jason Taylor who demonstrates along with Elmo (First: Episode 4167)
• Persistent, with David Beckham who was interrupted by Elmo (First: Episode 4168)
• Unanimous, with LL Cool J, Elmo, and Abby Cadabby, who were interrupted by Oscar the Grouch. (First: Episode 4169)
• Rhythm (film shown (EKA: Episode 3797)) (First: Episode 4170)
• Glockenspiel, with Randy Jackson who helped a dog who loves music (First: Episode 4171)
• Half, with Chandra Wilson who was helped by Murray Monster (First: Episode 4172)
• Disguise, with Jack Black who was not fooled by Elmo. (First: Episode 4173)
• Curly, with Neil Patrick Harris who was helped by Elmo. (First: Episode 4174)
• Frightened (film of a boy sleeping with a monster) (First: Episode 4175)
• Stuck, with Patrick Warburton who has a chicken stuck in his shirt. (First: Episode 4176)
• Brush (via Great Moments in the Sink) (First: Episode 4177)
• Cheer (film montage of three groups of men (three in each group)) (First: Episode 4178)
• Penguin (segment starring the penguins from Antarctica) (First: Episode 4179)
• Mustache, with Jonah Hill who is showing his own to Elmo. (First: Episode 4180)
• Friend (song sung by Cookie Monster) (First: Episode 4181)
• Distract, with Megan Mullally who was interrupted by many Muppet animals. (First: Episode 4182)
• Cactus (Cowboy pattern film in HD) (First: Episode 4183)
• Scrumptious, with Jessica Alba with a cake. (First: Episode 4184)
• Robot (film only) (First: Episode 4185)
• Fabulous, with Kim Cattrall along with Abby Cadabby, a shoe, and Rico the Robot (First: Episode 4186)

Season 40

• Habitat, with Cameron Diaz and woodland animals (First: Episode 4187)
• Pair, with Sarah Jessica Parker and Elmo (First: Episode 4188)
• Pollinate, with Nancy O'Dell, a flower and a bee (First: Episode 4189)
• Nature, with Debra Messing, a frog, a plant and a rock (First: Episode 4190)
• Season, with Adrian Grenier, Elmo and the Season-Bot 3000 (First: Episode 4191)
• Quest, with Tiki Barber, Oscar the Grouch, Grover and Cookie Monster (First: Episode 4192)
• Hibernate, with Meredith Vieira and woodland animals (First: Episode 4193)
• Surprise, with Maggie Gyllenhaal, Elmo, Zoe, Abby Cadabby, Grover, Rosita and Telly (First: Episode 4194)
• Brilliant, with Paul Rudd and Grover (First: Episode 4195)
• Machine, with Greg Kinnear and a robot (First: Episode 4196)
• Crunchy, with Adam Sandler and Cookie Monster (First: Episode 4197)
• Garden, with Jennie Garth and Abby Cadabby (First: Episode 4198)
• Camouflage, with Elisabeth Hasselbeck and a frog (First: Episode 4199)
• Separate, with Jake Gyllenhaal and an octopus (First: Episode 4200)
• Metamorphosis, with Patricia Arquette and Abby Cadabby (First: Episode 4201)
• Canteen, with Cedric the Entertainer and Abby Cadabby (First: Episode 4202)
• Speedy, with Brendan Fraser (First: Episode 4203)
• Stumble, with Ricky Gervais (First: Episode 4204)
• Inspect, with Jimmy Fallon (First: Episode 4205)
• Bones, with Matthew Fox, Elmo and a Bone (First: Episode 4206)
• Miniature, with Kobe Bryant and Abby Cadabby (First: Episode 4207)
• Booth, with Christina Applegate and Elmo (First: Episode 4208)
• Concentrate, with Hugh Jackman (First: Episode 4209)
• Spectacular, with Judah Friedlander (First: Episode 4210)
• Humongous, with Debi Mazar (First: Episode 4211)
• Exquisite, with Eva Longoria (First: Episode 4212)

Season 41

• Challenge, with Amy Poehler (First: Episode 4213)
• Journal, with Wanda Sykes (First: Episode 4214)
• Comfort, with Jason Bateman (First: Episode 4215)
• Cling, with Jude Law (First: Episode 4216)
• Pasta, with Kara DioGuardi (First: Episode 4217)
• Activate, with Chris O'Donnell (First: Episode 4218)
• Investigate, with Colin Farrell (First: Episode 4219)
• Appetite, with Reggie Bush (First: Episode 4220)
• Binoculars, with Julie Bowen (First: Episode 4221)
• Float, with Natalie Morales (First: Episode 4222)
• Allergic, with Taye Diggs and Idina Menzel (First: Episode 4223)
• Hexagon, with Ty Burrell (First: Episode 4224)
• Accessory, with Rebecca Romijn (First: Episode 4225)
• Arachnid, with Jim Parsons (First: Episode 4226)
• Incognito, with Terrence Howard (First: Episode 4227)
• Recipe, with Alton Brown (First: Episode 4228)
• Galoshes, with Jennifer Garner (First: Episode 4229)
• Crunchy, with Adam Sandler (First: Episode 4230)
• Identical, with Sherri Shepherd (First: Episode 4231)
• Reporter, with Samantha Harris (First: Episode 4232)
• Healthy, with Ellen Pompeo (First: Episode 4233)
• Volunteer, with Usher (First: Episode 4234)
• Gem, with Anna Faris (First: Episode 4235)
• Dozen, with Rachel Griffiths (First: Episode 4236)
• Celebration, with LaDainian Tomlinson (First: Episode 4237)
• Transportation, with Zoe Saldana (First: Episode 4238)

Season 42

• Engineer, with James Marsden (First: Episode 4257)
• Experiment, with Craig Ferguson (First: Episode 4258)
• Liquid, with George Lopez (First: Episode 4259)
• Observe, with Jerry O'Connell (First: Episode 4260)
• Transform, with Johnny Galecki (First: Episode 4261)
• Baile, with Sofia Vergara (First: Episode 4262)
• Fragile, with Jesse Tyler Ferguson (First: Episode 4263)
• Exchange, with Naomi Watts and Liev Schreiber (First: Episode 4264)
• Include, with Mila Kunis (First: Episode 4265)
• Empathy, with Mark Ruffalo (First: Episode 4266)
• Embarrassed, with Seth Rogen (First: Episode 4267)
• Fascinating, with Michelle Monaghan (First: Episode 4268)
• Sibling, with Jimmy Kimmel (First: Episode 4269)
• Compare, with Amar'e Stoudemire and Carmelo Anthony (First: Episode 4270)
• Ingredient, with Amy Adams (First: Episode 4271)
• Balance, with Emma Stone (First: Episode 4272)
• Amphibian, with Conan O'Brien (First: Episode 4273)
• Measure, with Drew Brees (First: Episode 4274)
• Stubborn, with Nicole Kidman (First: Episode 4275)
• Soggy, with John Krasinski (First: Episode 4276)
• Deciduous, with Ken Jeong (First: Episode 4277)
• Senses, with Maria Menounos (First: Episode 4278)
• Prickly, with Joel McHale (First: Episode 4279)
• Conflict, with Robin Williams (First: Episode 4280)
• Magnify, with Rico Rodriguez (First: Episode 4281)
• Stupendous, with Gustavo Dudamel (First: Episode 4282)

Season 43

• Nibble, with Halle Berry (First: Episode 4301)
• Champion, with Blake Griffin (First: Episode 4302)
• Remember, with Eric Stonestreet (First: Episode 4303)
• Careful, with Casey Affleck (First: Episode 4304)
• Patience, with Zac Efron (First: Episode 4305)
• Grimace, with Ed Helms (First: Episode 4306)
• Career, with Sonia Sotomayor (First: Episode 4307)
• Tool, with Jay Mohr (First: Episode 4308)
• Proud, with Timothy Olyphant (First: Episode 4309)
• Veterinarian, with Wendy Williams (First: Episode 4310)
• Vote, with Steve Carell (First: Episode 4311)
• Brainstorm, with Maya Rudolph (First: Episode 4313)
• Paleontologist, with Amy Ryan (First: Episode 4314)
• Splatter, with Kristen Bell (First: Episode 4316)
• Amplify, with Dax Shepard (First: Episode 4317)
• Attach, with Matt Kemp (First: Episode 4318)
• Innovation, with Paula Patton (First: Episode 4319)
• Choreographer, with Melissa McCarthy (First: Episode 4321)
• Sculpture, with Jon Hamm (First: Episode 4322)
• Inflate, with Don Cheadle (First: Episode 4324)
• Reinforce, with Joseph Gordon-Levitt (First: Episode 4325)