DictionaryultimoPrevious month
adverb / noun

ultimo

UL-tuh-moh/ˈʌltəˌmoʊ/

Referring to the previous month in dated correspondence.

I acknowledge receipt of your letter of the 12th ultimo.

Two adjacent desk calendar pages display only AUG and SEP; an arrow from SEP points back to a circled date on AUG, clearly the previous month.
Etymology

Latin ultimus meant 'last'; in the expression behind ultimo, the understood noun was 'month.' Thus 'last' identifies the preceding calendar month rather than an unspecified recent time.

More examples

  • Your invoice of the 5th ultimo remains unpaid.
  • We refer to the agreement signed on the 20th ultimo.
  • In a letter dated June 8, “3rd ultimo” means May 3.

Forms

ultimo