n.
Function: preposition
Date: before 12th century
1 a : in or to a place or situation in back of or to the rear of <look behind you> <put behind bars> b ― used as a function word to indicate something that screens an observer <the sun went behind a cloud> c : following in order <marched behind the band>
2 ― used as a function word to indicate backwardness, delay, or deficiency < behind the times> < behind schedule> <lagged behind last year's sales>
3 a : in the background of <the conditions behind the strike> b : out of the mind or consideration of <put our troubles behind us> c : beyond in depth or time <the story behind the story> <go back behind St. Augustine>
4 a : in support of : on the side of <solidly behind the candidate> b : with the support of <won 1-0 behind brilliant pitching>