† inˈvalidable,a.Obs.rare. [f. as next + -able.] Of no force or effect; ineffective. 1634Sir T. Herbert Trav. 109 Some attempts he used but invalidable; to shoot darts or arrowes at it was one with ayming at the moone.1638Ibid. (ed. 2) 315 The wals..are reasonable strong; but invalidable against..Cannon.