efficax

Latin

Etymology

From efficiō (“I make out, work out”) +‎ -āx (“inclined to”).

Pronunciation

• (Classical Latin) IPA^(key): /ˈef.fi.kaːks/, [ˈɛfːɪkäːks̠]
• (modern Italianate Ecclesiastical) IPA^(key): /ˈef.fi.kaks/, [ˈɛfːikäks]

Adjective

efficāx (genitive efficācis, adverb efficāciter); third-declension one-termination adjective

1. efficacious, effectual, powerful, efficient

Declension

Third-declension one-termination adjective.

Number	Singular			Plural
Case / Gender	Masc./Fem.	Neuter		Masc./Fem.	Neuter
Nominative	efficāx			efficācēs	efficācia
Genitive	efficācis			efficācium
Dative	efficācī			efficācibus
Accusative	efficācem	efficāx		efficācēs	efficācia
Ablative	efficācī			efficācibus
Vocative	efficāx			efficācēs	efficācia

Derived terms

• efficāciter

Descendants

• →⇒ English: efficacious
• → French: efficace
• → Italian: efficace
• → Spanish: eficaz

References

• “efficax”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• “efficax”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
• efficax in Charles du Fresne du Cange’s Glossarium Mediæ et Infimæ Latinitatis (augmented edition with additions by D. P. Carpenterius, Adelungius and others, edited by Léopold Favre, 1883–1887)
• efficax in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.