Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
acquit [əˈkwɪt] vt (LAW) опра́вдывать (оправда́ть perf)
to acquit o.s. well хорошо́ проявля́ть (прояви́ть*perf) себя́
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.