Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
brood [bruːd] n вы́водок#
vi (hen) сиде́ть*(impf) на я́йцах (person) размышля́ть (impf)
brood on or over vt fus грусти́ть*(impf) or размышля́ть (impf) о +prp
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.