What does canon mean in music a words?

1. A composition in which a melody is imitated in strict repetition at different pitch levels or time intervals. Canons may be for two or more voices or instruments. For one or more performers only if there is more than 1 part, then one performer can play several parts if desired.

2. Also in music terms an authoritative collection of sacred scriptures as recognized by a particular religious tradition such as Jewish or Christian writings.