ornament

Short definition from Wiktionary

Noun

1. 1
   An element of decoration; that which embellishes or adorns.
2. 2
   A Christmas tree decoration.
3. 3
   A musical flourish that is unnecessary to the overall melodic or harmonic line, but serves to decorate that line.
4. 4
   The articles used in church services.
5. 5
   A characteristic that has a decorative function (typically in order to attract a mate)

Verb

1. 1
   To decorate.
2. 2
   To add to.