Etymology
Proposed to derive from Proto-Italic *atnos, from Proto-Indo-European *h₂ét-no-, probably from *h₂et- (“to go”). Cognate with Oscan akno- (“year, holiday, time of offering”); Gothic *𐌰𐌸𐌽 (*aþn) or *𐌰𐌸𐌽𐍃 (*aþns, “year”), attested in 𐌰𐍄𐌰𐌸𐌽𐌹 (ataþni, “year”); and dialectal Dutch aden (“year”).
For the root, compare Sanskrit अतति (atati, “he wanders, goes”). For a comparable case of *-tn- yielding a geminate -nn- in Latin, see penna (“feather”), from Proto-Italic *petnā.
References
- “annus”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
- “annus”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
- annus 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)
- annus in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.
- Carl Meißner, Henry William Auden (1894) Latin Phrase-Book, London: Macmillan and Co.
- (ambiguous) at the beginning of the year: initio anni, ineunte anno
- year by year; day by day: singulis annis, diebus
- a year from now: ad annum
- it is more than twenty years ago: amplius sunt (quam) viginti anni or viginti annis
- twenty years and more: viginti anni et amplius, aut plus
- twenty years ago: abhinc (ante) viginti annos or viginti his annis
- I have not seen you for five years: quinque anni sunt or sextus annus est, cum te non vidi
- he has been absent five years: quinque annos or sextum (iam) annum abest
- the division of the year (into months, etc.: anni descriptio
- the intercalary year (month, day): annus (mensis, dies) intercalaris
- Homer lived many years before the foundation of Rome: Homerus fuit multis annis ante Romam conditam
- how old are you: quot annos natus es?
- I am thirteen years old: tredecim annos natus sum
- I am in my thirteenth year: tertium decimum annum ago
- a boy ten years old: puer decem annorum
- to be entering on one's tenth year: decimum aetatis annum ingredi
- to be ten years old: decem annos vixisse
- to be more than ten years old, to have entered on one's eleventh year: decimum annum excessisse, egressum esse
- to be not yet twenty: minorem esse viginti annis
- I was ten years old at the time: tum habebam decem annos
- to reach one's hundredth year, to live to be a hundred: centum annos complere
- to reach one's hundredth year, to live to be a hundred: vitam ad annum centesimum perducere
- the addition of a few years: accessio paucorum annorum
- to happen during a person's life, year of office: in aetatem alicuius, in annum incidere
- to prolong the command for a year: imperium in annum prorogare
- (ambiguous) to be elected at the age required by law (lex Villia annalis): suo (legitimo) anno creari (opp. ante annum)
- to prolong a person's command: prorogare alicui imperium (in annum)
- (ambiguous) in the past year: praeterito anno (not praeterlapso)
- (ambiguous) last year: superiore, priore anno
- (ambiguous) (1) last year; (2) next year: proximo anno
- (ambiguous) in the following year: insequenti(e) anno (not sequente)
- (ambiguous) after a year has elapsed: anno peracto, circumacto, interiecto, intermisso
- (ambiguous) in the course of the year: anno vertente
- (ambiguous) at the beginning of the year: initio anni, ineunte anno
- (ambiguous) at the end of the year: exeunte, extremo anno
- (ambiguous) every fifth year: quinto quoque anno
- (ambiguous) in the fifth year from the founding of the city: anno ab urbe condita quinto
- (ambiguous) to be elected at the age required by law (lex Villia annalis): suo (legitimo) anno creari (opp. ante annum)
- “annus”, in Harry Thurston Peck, editor (1898), Harper's Dictionary of Classical Antiquities, New York: Harper & Brothers
- annus in Ramminger, Johann (2016 July 16 (last accessed)) Neulateinische Wortliste: Ein Wörterbuch des Lateinischen von Petrarca bis 1700, pre-publication website, 2005-2016
- “annus”, in William Smith et al., editor (1890), A Dictionary of Greek and Roman Antiquities, London: William Wayte. G. E. Marindin