the.com/valentine

means A sweetheart, or the card/gift sent to one, especially on February 14th.

from Named for Saint Valentine, an early Christian martyr about whom almost nothing reliable is known — there were possibly several Valentines martyred under Roman rule. The romantic association didn't come from his life but from the date: medieval writers, notably Chaucer, popularized the idea that birds chose their mates in mid-February, and the saint's feast day got swept up in that notion. The 'markup' tradition is a much later, entirely commercial addition.