Meanings

1. to enter; to go into
2. to join; to become a member of
3. (bound form) to conform to (as in 入時|入时[rù shí])
4. abbr. for 入聲|入声[rù shēng]
5. (on product packaging, after {number n} + {classifier}) containing (n pieces) (from Japanese 入 'iri')