Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
behind [bɪˈhaɪnd] prep (at the back of) за +instr, позади́ +gen (supporting) за +instr (lower in rank etc) ни́же +gen
adv сза́ди, позади́
n (buttocks) зад#
behind the scenes за кули́сами
we're behind them in technology мы отста́ли от них в техноло́гии
to be behind schedule отстава́ть*(отста́ть*perf) от гра́фика
to leave sth behind (forget) оставля́ть (оста́вить*perf) что-н
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.