/pis"ant'/ , n.
1. Slang ( vulgar ). a person or thing of no value or consequence; a despicable person or thing.
2. Obs. an ant.
adj.
3. Slang ( vulgar ). insignificant or worthless.
Also, piss-ant .
[ 1655-65, in sense "ant"; PISS + ANT, prob. orig. on the model of PISMIRE ]