7 letters · 13 points in Scrabble
verb declare invalid
verb show to be invalid
verb make ineffective by counterbalancing the effect of
originEtymology tree English null Latin -i- Proto-Indo-European *dʰeh₁-der. Proto-Italic *-fakāō Latin -ficō Latin -ificāreder. Old French -ifierbor. Middle English -ifien English -ify English nullify From null + -ify.
Etymology from Wiktionary, CC BY-SA 3.0