1) An insult, similar to "fuck you" or "you suck"; 2) a phrase used to describe when things are less than optimal, similar to "this sucks"; 3) to receive an erect penis into a body orifice.
Committing suicide by inhaling methane gas from heating pipes or ovens. A more common suicide method in the earlier 20th century. Also used as a way to tell somebody off.
Aunt Angie was so depressed when she found out about Uncle Charlie cheating on her that she took the gas pipe.