efficax

Forms

efficāx (genitive efficācis, adverb efficāciter); third-declension one-termination adjective^[1]

Etymology

It is from Latin efficiō (“to bring about, accomplish”) + -āx.^[2][3][1] efficiō is formed from ex- and faciō (“to do, make”).^[1] Late grammarians explained it as “taking effect”, and Priscian as a compound of altered forms of ⟨ex⟩ and ⟨fac-⟩.^[3]

Earliest recorded meaning

Köbler finds it first in Marcus Caelius Rufus,^[4] who writes to Cicero how slow and ineffective a certain Marcellus is.^[2][5]

Semantic evolution

It means effective, able to do what is required, of persons, as Horace's mighty Hercules, and of things, above all medicines and charms: Horace yields to an effective magic art, and Pliny the Elder often calls a plant effective against a complaint or very effective against arrow wounds.^[2][5] In law it is valid, as in Ulpian.^[2] Lewis & Short note that it is mostly post-Augustan and absent from Cicero and Caesar.^[5] English efficacious was formed from its stem in the 1520s.^[6]

Timeline

• 1st century BC – Caelius of an ineffective man.^[2][4]
• 65–8 BC – Horace of Hercules and of a magic art.^[2][5][4]
• 23/24–79 AD – Pliny the Elder of effective remedies.^[2][5][4]
• before 223 AD – Ulpian of a legally valid act.^[2][4]
• 1520s – English efficacious is formed from it.^[6]

Meanings

Adjective

1. Effective, efficient, powerful, of persons.^[2][5][1]
2. Of things, especially remedies, efficacious, effectual.^[2][5][7][1]
3. (law) Valid.^[2]

Word family

• efficācia
• efficācitās
• inefficāx

References

1. ^ a b c d e f g Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k Glare, P. G. W., ed. (2012), Oxford Latin Dictionary, 2nd ed., Oxford: Oxford University Press
3. ^ a b Thesaurus linguae Latinae (1900–), Leipzig: Teubner; Berlin: De Gruyter; open-access ed., Munich: Bayerische Akademie der Wissenschaften
4. ^ a b c d e Köbler, Gerhard (2010), Lateinisches Abkunfts- und Wirkungswörterbuch für Altertum und Mittelalter, online ed., koeblergerhard.de
5. ^ a b c d e f g Lewis, Charlton T.; Short, Charles (1879), A Latin Dictionary, Oxford: Clarendon Press
6. ^ a b Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
7. ^ Stelten, Leo F. (1995), Dictionary of Ecclesiastical Latin, Peabody, Mass.: Hendrickson