Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
groan [grəun] n (of person) стон
vi (person, in pain) стона́ть*(impf) (:in disapproval) тяжело́ вздыха́ть (вздохну́ть perf) (tree, floorboard) скрипе́ть (impf)
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.
Русский: