smyku
Smyku is a grammatical form in Polish most commonly recognized as the vocative and locative form of the noun smyk. The base word smyk is an informal term meaning a small child, youngster, rascal or a nimble, quick person; it is used affectionately or colloquially rather than in formal registers.
As a declensional form, smyku is used when addressing someone directly (vocative), for example when calling
Beyond grammar, smyku can occur as part of proper names, trade names, product branding, nicknames and occasional