valentinenoun [ C ]
uk/ˈvæl.ən.taɪn/us/ˈvæl.ən.taɪn/someone you love or would like to have a romantic relationship with:
The message on the card said "Be my Valentine!"
also valentine card a decorative card that you send, sometimes without your name on it, on 14 February (Valentine's Day) to someone you love:
Did you get any valentines?
I left a valentine card in her locker.