n.
Pronunciation: ˌ am-p ə - ' si-l ə n
Function: noun
Etymology: am ino + p en icillin
Date: 1961
: a penicillin C 16 H 19 N 3 O 4 S that is effective against gram-negative and gram-positive bacteria and is used to treat various infections of the urinary, respiratory, and intestinal tracts