From WordNet (r) 3.0 (2006):
stag
n 1: a male deer, especially an adult male red deer [syn:
hart, stag]
2: adult male deer
v 1: attend a dance or a party without a female companion
2: give away information about somebody; "He told on his
classmate who had cheated on the exam" [syn: denounce,
tell on, betray, give away, rat, grass, shit,
shop, snitch, stag]
3: watch, observe, or inquire secretly [syn: spy, stag,
snoop, sleuth]