look up any word, like dirty sanchez:
 
3.
UCA
United Combat Alliance, an online gaming militaristic-rank clan that plays under NovaLogic and Valve titles.

Formed in 2004.
Names:

UCA-Pvt-Adam

United Combat Alliance - Private - Adam
by MRSHADOW66 June 29, 2010
 
1.
University College Application Service, or something like that. Basically a service that allows you to apply for universities that is so incredibley long winded and complex that you loose the will to live as one uni after another rejects you.
"You have been rejected from <insert univeristy name here>. Better luck next year!"

Bastards.
by Bone Idle Student March 03, 2005
 
2.
UCA
The United Clan of Assassins. UCA is the best clan for Call of Duty, Call of Duty United Offensive and Call of Duty 2.

Phil: Whats up Steven?

Steven: Oh, not much. I was just pwned by UCA again.

by .:[UCA]:.S4ntiago May 18, 2007
 
4.
A form. Not to be confused with the bionic, even though it does cost £6M maaaaan, understaaaaand? Me neither.
"John Evans please sign for your UCAS form again" - Noddy Holder
by Cunt von Cunt November 06, 2003