postcard
n. countable A2 Elementary US //ˈpoʊˌskɑɹd// UK //pˈəʊstkɑːd// post·card
n. a card with a picture on one side that you can send through the mail without an envelope. You usually write a short message on the back to tell friends about your holiday.
n. a rectangular card for sending a message by post without an envelope, typically featuring a photograph or illustration on one side.
I sent a postcard to my parents from Rome.
She bought a vintage postcard at the market to keep as a souvenir of her trip to the coast.
Before the era of instant digital communication, sending a postcard was the standard way to share travel experiences with friends and family back home.
From post + card.
Usage
Often used with the verbs 'send', 'write', or 'mail'.