smart-aleck

Translations
умник
самоуверенный умник
нахальный умник
всезнайка
умничающий
Definitions
A person who behaves in an irritatingly self-confident way, especially by showing off their knowledge or cleverness.
Characterized by an irritatingly self-confident display of cleverness or knowledge.
Words
smart

adjective
умный
aleck

noun
умник