1540s, from Middle French conjugal (13c.), from Latin coniugalis "relating to marriage," from coniunx (genitive coniugis) "spouse," related to coniugare "to join together," from com- "together" (see com-) + iugare "to join," from iugum "yoke" (see jugular).
A descriptive term for the relationship between married persons. A conjugal family is the same as a nuclear family, composed of married parents and their children. Conjugal relatives (in-laws) trace their relations through the marriage of their respective blood relatives.