From Wiktionary, the free dictionary
Borrowed from Old Church Slavonic -ушька (-ušĭka).
-ușcă f (plural -uște)
- Forms feminine diminutives of nouns.
- muiere (“woman”) + -ușcă → muierușcă (“little woman”)
- rață (“duck”) + -ușcă → rățușcă (“ducky”)
- mierlă (“blackbird”) + -ușcă → mierlușcă (“small blackbird”)