FromLatinper annum(“yearly”), fromannus(“year”).

annum (pluralannums)

1. Synonym ofyear,particularly
   1. (uncommon) Aone-yearperiod,particularly(finance) afiscal year or(sciences) aJulian year ofexactly 365.25days.

      Coordinate terms:biennium,triennium,quadrennium,quinquennium,sexennium,septennium,octennium,novennium,decennium,vicennium,tricennium,centennium,quincentennium,millennium,decamillennium,centimillennium,millionennium

   2. (uncommon,science fiction) A "year"determined by therevolution of anextraterrestrialplanet.

Most frequently used in the set phraseper annum or compounds used in scientific dating.

• (abbreviation)a.,ann.

• kiloannum,mega-annum,giga-annum

• nanmu,unman

annum m

1. accusativesingular ofannus(“year”)

• gigaannum
• kiloannum
• megaanum
• per annum