9 letters · 12 points in Scrabble
noun a feature (quantity or property or function) that remains unchanged when a particular transformation is applied to it
adjective unaffected by a designated operation or transformation
adjective unvarying in nature
originEtymology tree Proto-Indo-European *né Proto-Indo-European *n̥- Proto-Italic *n̥- Latin in-bor. Middle English in- English in- English variant English invariant From in- + variant.
Etymology from Wiktionary, CC BY-SA 3.0