I am looking for the etymology of the Latin adjective "anterior" (which is also a Spanish word, with the same meaning). Neither Wiktionary nor L&S provide hints on its etymology. It seems intuitive to me that this word derives from the combination of "ante" and "prior". The latter, in its adjective form is declined in the third declension, just as anterior is.
But, is this the etymology of the word? In particular, in which sense would be anterior the combination of the meanings of ante and prior? For what I can see, anterior more or less inherited without modification some of the meanings of these words (Wiktionary etymology 1 from 1 of adverb of ante, and etymology 2 from 1 of adjective of prior. But then why a new word?