inefficax
From LSJ
Latin > English (Lewis & Short)
ĭn-effĭcax: ācis, adj.,
I ineffectual, inefficient (post-Aug.).
(a) With gen.: vox inefficax verborum, unproductive of, unable to produce, Sen. Ira, 1, 3.—
(b) Absol.: ratio, Sen. Ira, 1, 10: dii, id. Ben. 4, 4.— Comp., Plin. 34, 11, 25, § 109: parentes inefficacissimi, i. e. very weak, Inscr. ap. Grut. 415, 10.—Adv.: ĭneffĭcācĭter, ineffectually, in vain, Dig. 49, 8, 2; Cod. Just. 6, 35, 2; Symm. Ep. 6, 53.