To be third-wheeled is to be intentionally left out of activities as part of a friend group. If you're third-wheeled, you're most definitely the convenience friend. They'll make you desperate to hang out, but never actually include you in anything. You can expect to be asked to hang out only if nobody else wants to.

If you notice you're being third-wheeled, it's probably a toxic friendship and you should get out of there.
Jim was third-wheeled by his friends so they always had someone to fall back to when they got bored.
by verwijder January 19, 2021
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Someone who is unknowingly tricked into actively working against their side and themselves. The word comes from the game Among Us which is a murder mystery game where there are 2 murderers called imposters.
Yellow: I was in O2
Blue: No you weren’t, I saw you vent in electrical.
Green: yellows clear, if he were imposter he’d have killed me many times. Blue I think you’re the imposter.
Blue: Stfu green. You realize you’re the third imposter, right?
by AmurrJuan September 15, 2020
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The term "the first and the third" refers to the two days of the month on which individuals receiving government financial assistance get their funds. On these days, some low-income and government housing projects prohibit their residents from receiving visitors so that the funds are not mismanaged. Generally, the term refers to the distribution of federal aid money (and not the other negative connotation).
Examples in pop-culture:
"And make 'em feel good like the first and the third." (Jeezy, from the song "My Hood," off the album "Let's Get It: Thug Motivation 101")
"Getting like like the first and the third." (Curren$y, from the song, "Coolie in the Cut," off the album "New Jet City")

Example of daily usage:
me: "Hi Caleb, I'm in the Tenderloin. Can I come visit?"
boyfriend: "No, it's the third. My building won't allow visitors today. People's checks just came in."
by donnauwanna February 4, 2016
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A person who feels left out by a couple or a pair of besties.
Being the third wheel, Ramona took a nice selfie only to find that Marchello and Nicole were photobombing as they were kissing!
by JRHU July 29, 2018
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Similar in concept to "the third wheel." When two lesbians are in a relationship and the third is tagging along (as a friend).
I had an amazing time with Michelle and Veronica this weekend, however, I couldn't help feeling like I was the third taco.
-Beyonce
by thefever March 24, 2014
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When there is a couple together, and one extra person there without a date, so they are 'third-wheeling' the couple.
Mary: You and Your boyfriend (Jack) go to the movies together.
Wendy: It will be boring without you though, can't you come?
Mary: Only if we invite another person so Im not a third wheeler
by RRRRRRAAAAACCCCCHHHHH September 30, 2013
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A person who hangs out with two other people. The two other people are closer to each other than the "Third Wheel". People generally feel awkward when the third wheel mentions how much it sucks to be the first wheel (They actually normally get mad).
-Did you invite Hannah?
-No, she's just the third wheel anyways
by IAmTheThirdWheel April 20, 2015
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