Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
margin [ˈmɑːdʒɪn] n (on page) поля́ ntpl (of group) перифери́я; (of area) край#; (difference, of victory) преиму́щество; (:of defeat) меньшинство́; (also: profit margin) ма́ржа, чи́стая при́быль f no pl
safety margin запа́с про́чности
margin of error преде́л допусти́мой погре́шности
they won by a margin of five votes они́ победи́ли с большинство́м в пять голосо́в
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.