Added 9 October 2026 proliferation /pɹəˌlɪf.əˈɹeɪ.ʃən/ noun Categories: ActionsUncommon Words noun ! Definition from WordNet 3.1, Princeton University. Pronunciation from Wiktionary, via Kaikki.org. More about proliferation at Wordnik → Where our words come from → Growth by the rapid multiplication of parts. A rapid increase in number (especially a rapid increase in the number of deadly weapons). the proliferation of nuclear weapons Related Words: breedingreproductioninfestationmushroomingbloomexpansionfloodinginundationmultiplicityspilloverdiffusionpropagation Back to today's word