Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
imposition [ɪmpəˈzɪʃən] n (of tax etc) обложе́ние
to be an imposition on sb быть*(impf) обу́зой кому́-н
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.
Русский: