Ornament
/ˈɔː(ɹ)nəmənt/
noun
An element of decoration; that which embellishes or adorns.
A Christmas tree decoration.
A musical flourish that is unnecessary to the overall melodic or harmonic line, but serves to decorate or "ornament" that line.
verb
To decorate.
“We will ornament the windows with trim to make the room seem brighter.”
To add to.
“The editor ornamented his plain writing, making it fancier but less clear.”