riff

Short definition from Wiktionary

Noun

1. 1
   A repeated melody line in a song, usually instrumental but sometimes vocal.
2. 2
   A clever or witty remark.
3. 3
   A variation on something.
4. 4
   A spoof.
5. 5
   The belly; the bowels.

Verb

1. 1
   To improvise in the performance or practice of an art, especially by expanding on or making novel use of traditional themes.
2. 2
   To riffle.
3. 3
   To tell jokes over a movie or similar performance.

Proper noun

1. 1
   Acronym of Resource Interchange File Format.
2. 2
   Alternative form of Rif (“mountains in Morocco”).