WordNet sense 1 (lacking originality or spontaneity; no longer new):

dusty, moth-eaten

WordNet sense 2 (not original; not being or productive of something fresh and unusual):

unoriginal

WordNet sense 3 (covered with or smelling of mold):

moldy

WordNet sense 4 (dried out):

hard

WordNet sense 5 (having lost freshness through passage of time):

cold

WordNet sense 6 ((of foodstuffs) not in an edible or usable condition):

spoiled