Alexander Dyce, A General Glossary to Shakespeare's Works

christom “child,” HENRY V., ii. 3. 11. The Hostess means chrisom child. On the line in The Doubtful Heir, “You shall be as secure as chrisom children, ” Gifford remarks, “Johnson says chrisom children are those that die within the month. It may be so; but our old writers apply the expression to a child just cristened.” Shirley's Works, vol. iv. p. 298 . Nares (in his Gloss.) quotes what follows from Blount's Glossography: “Chrisome (α χρίω [to anoint—with the holy oil formerly used in baptism]) signifies properly the white cloth which is set by the minister of baptism upon the head of a child newly anointed with chrism after his baptism. Now it is vulgarly taken for the white cloth put about or upon a child newly christened, in token of his baptism; wherewith the women use to shroud the child, if dying within the month; otherwise it is usually brought to church at the day of purification. Chrisoms, in the bills of mortality, are such children as die within the month of birth, because during that time they use to wear the chrisom-cloth.” (In the first edition of Blount's work, 1656, I do not find the concluding sentence of the above quotation.)