Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
cock [kɔk] n (rooster) пету́х#; (male bird) саме́ц#
vt (gun) взводи́ть*(взвести́*perf)
to cock one's ears (fig) навостри́ть (perf) у́ши
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.