effĭcācĭa

ae, f.

efficax

I. efficacy, efficiency, virtue (post-Aug.), Plin. 11, 5, 4, § 12; Amm. 14, 8, 5; 16, 12, 25; Vulg. Sirach, 9, 4; Lact. de Ira D. 10, 37.
Lewis & Short
A Latin Dictionary, 1879
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