sentences:  For example, "lunar rocket" and "moon rocket" are accepted as synonyms, as are "thermal capacity" and "heat capacity".However, in other cases the two words may have lexicalized uses so that one cannot replace the other, as in "nocturnal view" and "night view", or "feline grace" but "cat food" (not *"cat grace" or *"feline food").Collateral adjectives contrast with derived (denominal) adjectives.