What is the X in X-mas?
c.1400, "breeding, nursing," from Old French norture, norreture "food, nourishment; education, training," from Late Latin nutritia "a nursing, suckling," from Latin nutrire "to nourish, suckle" (see nourish). Meaning "place or room for infants and young children and their nurse" is from c.1300. As a type of school, 1580s. Horticultural sense is from 1560s. Nursery rhyme is from 1832.