13 letters · 18 points in Scrabble
adjective incapable of being justified or explained
originEtymology tree English un- English warrant Proto-Indo-European *-tḗr Proto-Indo-European *-dʰlom Proto-Indo-European *-dʰlis Proto-Italic *-ðlis Latin -bilis Latin -ābilis Old French -ablebor. Middle English -able English -able English warrantable English unwarrantable From un- + warrantable.
Etymology from Wiktionary, CC BY-SA 3.0