/ bɪˈhaɪnd; NAmE / preposition , adverb , noun
■ preposition
1.
at or towards the back of sb/sth, and often hidden by it or them :
Who's the girl standing behind Jan?
Stay close behind me.
a small street behind the station
She glanced behind her.
Don't forget to lock the door behind you (= when you leave) .
The sun disappeared behind the clouds.
—compare in front of ➡ note at back
2.
making less progress than sb/sth :
He's behind the rest of the class in reading.
We're behind schedule (= late) .
3.
giving support to or approval of sb/sth :
She knew that, whatever she decided, her family was right behind her.
4.
responsible for starting or developing sth :
What's behind that happy smile (= what is causing it) ?
He was the man behind the plan to build a new hospital.
5.
used to say that sth is in sb's past :
The accident is behind you now, so try to forget it.
She has ten years' useful experience behind her.
■ adverb
1.
at or towards the back of sb/sth; further back :
She rode off down the road with the dog running behind.
The others are a long way behind.
He was shot from behind as he ran away.
I had fallen so far behind that it seemed pointless trying to catch up.
2.
in the place where sb/sth is or was :
I was told to stay behind after school (= remain in school) .
This bag was left behind after the class.
3.
behind (with / in sth) late in paying money or completing work :
She's fallen behind with the payments.
He was terribly behind in his work.
■ noun
( informal ) a person's bottom. People often say 'behind' to avoid saying 'bottom'.
SYN backside :
The dog bit him on his behind.
••
WORD ORIGIN
Old English behindan , bihindan , from bi by + hindan from behind .