hackneyed
Meaning: unoriginal, trite
Usage: A girl can only hear “I love you” so many times before it begins to sound hackneyed and meaningless.
trite
Meaning: not original, overused
Usage: Keith thought of himself as being very learned, but everyone else thought he was trite because his observations about the world were always the same as David Letterman’s.
derivative
Meaning: taken directly from a source, unoriginal
Usage: She was bored by his music because she felt that it was derivative and that she had heard it before.