tri-annual

English

Etymology

From tri- +‎ annual.

Adjective

tri-annual (not comparable)

1. Alternative form of triannual.
   • 2023 September 6, Anthony Lambert, “Train paths: more space for freight?”, in RAIL, number 991, page 34:

     "I don't think moving to tri-annual timetable changes brings any benefit to the freight sector.