From Longman Dictionary of Contemporary EnglishPost-itˈPost-it (also Post-it note) noun [countable] trademarkBD a small piece of coloured paper that sticks to things, used for leaving notes for people
Examples from the Corpus
Post-it• These frontline soldiers are cheap, disposable small fry attached to writing pads, booklets, and smart Post-it notes.• Central Stores had never even stocked Post-it Notes.• There is no genius to stocking Post-it Notes, eliminating obsolete bureaus, and cutting costs.From Longman Business DictionaryPost-itˈPost-it (also Post-it note) noun [countable] trademark a small piece of sticky coloured paper, used for leaving notes for people or marking pages in a book