Russian

Noun

осложне́ние • ‎(osložnénije) n inan ‎(genitive осложне́ния, nominative plural осложне́ния, genitive plural осложне́ний)

1. complication (the act or process of complicating; the state of being complicated; intricate or confused relation of parts; entanglement)
2. (medicine) complication (a disease or diseases, or adventitious circumstances or conditions, coexistent with and modifying a primary disease, but not necessarily connected with it)

Declension