Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
cup [kʌp] n ча́шка#; (as prize) ку́бок#; (of bra) ча́шечка#
a cup of tea ча́шка*ча́я
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.
Русский: