Short for 'fuck a cactus.' Usually used as the predicate of a sentence.

It is also commonly used against someone who is stubborn and needs a rude awakening to what is actually occurring.
Jill: My mom is such a bitch.

Jane: I know, she seriously needs to fucactus.

Jill: Ow...
by BriFee June 20, 2009
Get the Fucactus mug.