Threeheat 

When you get pizza delivered, you reheat it, and the next day you heat it again for the third time.

My threeheated pizza still tasted awesome!

Threeheat by H8redsox October 16, 2020

Threelationship 

-noun

-an emotionally and sexually intimate relationship between three persons.

Man my threelationship is going great.

Isn't it rough, 3 guys in a relationship?

Threelationship by Eric Stevens January 5, 2008

Threelets 

Three identical siblings that share the same mother

My sisters and I are Threelets

My two brothers look exactly like me so were Threelets

Threelets by Briefcase Joe January 13, 2011

Threegether

Adverb: with or in proximity to two other people.

They were all threegether in bed.

Let us go to the movies threegether

Threegether by Pop Poodle November 23, 2019

Threedating

A combination of the following words: Three and E-dating.
It occurs when three different human being e-date each other at the same time.

Ethan: I'm threedating Eren and Oscar, my life couldn't have been any better!

Threedating by erenxstorm February 9, 2021

threehead 

When the hairline of a person is so low that their forehead becomes reclassified a "threehead". This also suggests that their forehead is only about three finger widths high.

"Boy's hairline is so low, he got a threehead."

threehead by hidispenser January 25, 2005

threematch 

When two division rival NFL teams meet each other a third time in a playoff matchup after playing each other twice during the regular season.

Can also be used as a synonym for rubber match or tiebreaker in a best-of-three series

The Ravens and Steelers, who each won a game during their home-and-away matchups earlier in the season, will square off in their threematch on Saturday in Pittsburgh. The winner of the threematch advances to the conference final, and the loser goes home.

threematch by Slamnanigans January 10, 2011