look up any word, like half chub:
 
1.
Tandem is a pair/match or the chemistry of two people

It is a commonly used word in the Philippines, especially when talking about their favorite couples in Filipino Dramas.
-Gusto ka talaga yung tandem nila
meaning:
-I really like their chemistry.
by silent-reader September 09, 2009
 
2.
The act of having sex while simultaneously being screwed in the ass.
I got tandemed last night by Gina and Rodger I can hardly walk.
by Dangerous Dave I August 17, 2005
 
3.
When 2 or more people are extremely high simultaneously, and they begin laughing at the same time with neither one knowing what is funny.
How about this tandem we got goin' on here? Now pass that blunt, bogart.
by Tweaked in B-Town November 13, 2005
 
4.
Adjective
A substitute for the politically incorrect term, "gay." Also can be used to describe something that is lame, unfortunate, or ridiculous or to replace the phrase, "no homo."
1. Dude! You're lookin' good today. No tandem.

2. You rollerblade to work? That is so tandem.

3. Mr. X: The bartender cut me off cuz I puked all over the pool table.
Mr. Y: That's tandem.
by LekSickOn April 04, 2009