Meaning

adjective so extremely old as seeming to belong to an earlier period

adjective little evolved from or characteristic of an earlier ancestral type

originFrom archaism (“ancient or obsolete phrase or expression”) or from French archaïque, ultimately from Ancient Greek ἀρχαϊκός (arkhaïkós, “old-fashioned”), from ἀρχαῖος (arkhaîos, “from the beginning, antiquated, ancient, old”), from ἀρχή (arkhḗ, “beginning, origin”), from ἄρχω (árkhō, “to be first”), from ἄρχω (árkhō, “to begin”), from Proto-Indo-European *h₂ergʰ- (“to begin, rule, command”).

Etymology from Wiktionary, CC BY-SA 3.0