look up any word, like donkey punch:
 
1.
the groove is a slow, driving, funk based rythm. the groove can only be played by someone who has already heard the groove. the groove is deep. the groove can move. the groove is heavy.
"Man cat, the groove is so deep you can see the other side."
by the groove November 03, 2005
 
2.
when you've got the perfect buzz in beirut, so you're more relaxed about making shots, but not so drunk that you miss them all.
"Joe and I totally dominated in beer pong last night! We were in the groove, but the other guys were tanked."
by Jack324 April 08, 2007
 
3.
At the age (usually 16 or so) when you are extremely sexually active or when 'in the groove' you are noticed more for your youth, freshness and in particular your physical attributes.
"Man, I think she'll put out tonight, she's in the groove right now."
by JLBCEL July 28, 2009