Added 10 October 2026 self-acting adjective Categories: Describing Words adjective ! Definition from WordNet 3.1, Princeton University. More about self-acting at Wordnik → Where our words come from → Designed to activate or move or regulate itself. a self-activating sprinkler system Origin From self- + acting. From Wiktionary, via Kaikki.org (CC BY-SA) Related Words: self-regulatingautomaticself-activatingself-movingautonomousself-startingself-executingself-existentoff-bookself-emptyingself-sufficientactless Back to today's word