Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
poorly [ˈpuəlɪ] adv пло́хо
adj
she is feeling poorly она́ пло́хо себя́ чу́вствует
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.
Русский: