acus

Latin

Pronunciation

• (Classical) IPA^(key): /ˈa.kʊs/

Etymology 1

From Proto-Indo-European *h₂eḱ- (“sharp”). Related to acuō (“sharpen, whet”) and aciēs (“edge”).

Noun

acus f (genitive acūs); fourth declension

1. a needle, a pin
2. bodkin

Inflection

Fourth declension.

Case	Singular	Plural
Nominative	acus	acūs
Genitive	acūs	acuum
Dative	acuī	acibus
Accusative	acum	acūs
Ablative	acū	acibus
Vocative	acus	acūs

Derived terms

Derived terms

• acia
• acuārius
• acucula
• acula

• aculeus
• acuō
• acū pingō (“I embroider”)

• aquifolium
• foramen acūs (“the eye of a needle”)
• rem acū tetigistī, acū tetigistī

Descendants

• Aromanian: ac
• Dalmatian: juac
• English: acupuncture
• Istriot: ago

• Italian: ago
• Romanian: ac
• Sardinian: àcu
• Vulgar Latin: *acūcla (see there for further descendants)

Etymology 2

From Proto-Indo-European *h₂eḱ- (“sharp”), cognates including agna (“ear”) and Proto-Germanic *ahaz (“ear”), Proto-Germanic *aganō, *ahanō (“chaff”) (> English awn), Ancient Greek ἄχυρον (ákhuron), Greek άχυρο (áchyro, “hay”).

Noun

acus n (genitive aceris); third declension

1. bran

   Synonym: āplūda

Inflection

Third declension neuter.

Case	Singular	Plural
Nominative	acus	acera
Genitive	aceris	acerum
Dative	acerī	aceribus
Accusative	acus	acera
Ablative	acere	aceribus
Vocative	acus	acera

Derived terms

• acerātus
• acerōsus

References

• Ernout, Alfred; Meillet, Antoine (2001), “acus”, in Dictionnaire étymologique de la langue latine: histoire des mots (in fr), with additions and corrections of André J., 4th edition, Paris: Klincksieck, page 7
• acus in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• acus in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
• acus in Charles du Fresne du Cange’s Glossarium Mediæ et Infimæ Latinitatis (augmented edition, 1883–1887)
• acus in Gaffiot, Félix (1934) Dictionnaire Illustré Latin-Français, Hachette
• Carl Meissner; Henry William Auden (1894) Latin Phrase-Book‎^[1], London: Macmillan and Co.
  • you have hit the nail on the head: rem acu tetigisti
    
• acus in Harry Thurston Peck, editor (1898) Harper's Dictionary of Classical Antiquities, New York: Harper & Brothers
• acus in William Smith et al., editor (1890) A Dictionary of Greek and Roman Antiquities, London: William Wayte. G. E. Marindin