Added 9 October 2026 adulthood noun Categories: TimeDescribing WordsUncommon Words noun ! Definition from WordNet 3.1, Princeton University. More about adulthood at Wordnik → Where our words come from → The period of time in your life after your physical growth has stopped and you are fully developed. The state (and responsibilities) of a person who has attained maturity. Related Words: maturitygrown-upgrownupmatureagemajoritypubertyprimemanhoodwomanhood Back to today's word