Timing sexual intercourse to avoid the time of ovulation (if pregnancy is not wanted) or to fall within that time (if pregnancy is desired).

plural of foster family

(Mormonism) An evening, usually Monday, set apart once a week for family activity such as lessons, games, and prayer.

plural of royal family

(genetics) A group of closely related genes that make similar gene products.

plural of gene family

(marketing, singular only) A size for a container of goods, among the largest sizes meant for sale to a householder consumer.

(pathology) a hereditary inflammatory disorder, characterized by recurrent fever, that affects groups of people originating from around the Mediterranean Sea, including Armenians, Sephardi Jews, Greeks, and Arabs

plural of nuclear family

(idiomatic) To be a characteristic feature that is observed in several generations of a family.