12 letters · 17 points in Scrabble
noun any animal lacking a backbone or notochord; the term is not used as a scientific classification
adjective lacking a backbone or spinal column
originEtymology tree Proto-Indo-European *né Proto-Indo-European *n̥- Proto-Italic *n̥- Latin in-bor. Middle English in- English in- English vertebrate English invertebrate From in- + vertebrate.
Etymology from Wiktionary, CC BY-SA 3.0