Added 9 October 2026 darkening noun Categories: ActionsRare Words noun ! Definition from WordNet 3.1, Princeton University. More about darkening at Wordnik → Where our words come from → Changing to a darker color. adjective Becoming dark or darker as from waning light or clouding over. the darkening sky Related Words: darkblackeningdeepeningblackenizationreddeningbrowninglighteningquieteningshadingdyeingalbescencedemagnification Back to today's word