ultimo

/ˈʌltɪmoʊ/
adverb
  1. In or of the month before the current one (used in formal or business writing).
    • Your letter of the 15th ultimo has been received and reviewed.
    • We shipped the order on the 20th ultimo, so it should arrive soon.
    • The invoice dated 10th ultimo is now overdue for payment.
Antonyms