Literally, “on [the] side”.
na boku (not comparable)
- (idiomatic) on one side, to one side, aside (situated to one side or out of the way)
- (idiomatic) on the side, unofficially
- (idiomatic) apart, aloof
- Synonyms: z dala, z daleka
- na boku in Wielki słownik języka polskiego, Instytut Języka Polskiego PAN
- na boku in Polish dictionaries at PWN