Stepchild

n.	1.	A bereaved child; one who has lost father or mother.
	2.	A son or daughter of one's wife or husband by a former marriage.

Noun

1.

stepchild - a child of your spouse by a former marriage

child, daughter, descendant, foster child, grandchild, granddaughter, grandson, heiress, offspring, scion, son, son and heir, sonny, stepbrother, stepdaughter, stepfather, stepmother, stepsister, stepson