Added 9 October 2026 platelet /ˈpleɪt.lət/ noun Categories: NatureUncommon Words In Latin: thrombocytus Wiktionary noun ! Definition from Wiktionary (CC BY-SA). Pronunciation from Wiktionary, via Kaikki.org. More about platelet at Wordnik → Where our words come from → A small colorless disk-shaped particle found in the blood of mammals, which plays an important role in the formation of blood clots. Related Words: thrombocyteblisterderivedlamellawaferfrictionplaquepadnametagbookletprocessing Back to today's word