no no

Short definition from Wiktionary

Noun

1. 1
   Alternative form of no-no.
2. 2
   Something that is forbidden, prohibited, discouraged or taboo.
3. 3
   A no-hitter; a game in which no batter on one of the teams got a hit.

Interjection

1. 1
   Used to fervently deny something.
2. 2
   Response to ahoy if no officer is in the boat.