From Longman Dictionary of Contemporary Englishvalentineval‧en‧tine /ˈvæləntaɪn/ noun [countable] 1 LOVEsomeone you love or think is attractive, that you send a card to on St Valentine’s Day Be my valentine.2 TCMa card you send to someone on St Valentine’s Day
Examples from the Corpus
valentine• Who could the woman be, who admired him so much that she sent him a valentine?• A group of nineteenth century greeting cards and valentines, types of ephemera now a popular field of collecting.• Every year she bought a dozen valentines.• But she would have preferred him to admire her from the beginning, without the encouragement of her valentine.• The other valentines were a more complicated matter.• Bathsheba was about to ask why he should think that, when she remembered the valentine.Origin valentine (1400-1500) Saint Valentine 3rd-century Italian priest 