decoration (n)
ornament (n)
ornamentation (n)

Definition: something used to beautify

ornament (v)

Definition: be an ornament to
Example: stars ornamented the Christmas tree.

adorn (v)
beautify (v)
decorate (v)
embellish (v)
grace (v)
ornament (v)

Definition: make more attractive by adding ornament, colour, etc.
Example: Decorate the room for the party. beautify yourself for the special day.