a card used for sending messages by post without an envelope, especially one that has a picture on one sidecolourful postcards of CaliforniaSend us a postcard from Venice!Send your answers on a postcard to the above address.see alsopicture postcardOxford Collocations Dictionaryadjectivepicture,holidayverb + postcardwrite,mail,post,…postcard + verbarrive,come,depict something,…prepositionon a/the postcard,postcard from,postcard of,…Seefull entryExtra examplesI hate writing holiday postcards.I sent him a postcard of the cathedral.Write your answers on a postcard.
See postcard in the Oxford Advanced American Dictionary