1640s, "exert weight; move downward" (obsolete), from Modern Latin gravitare (16c. in scientific writing), from Latin gravitas "heaviness, weight," from gravis "heavy" (from PIE root *gwere-(1) "heavy"). Meaning "be affected by gravity" is from 1690s. Figurative sense "be strongly attracted to, have a natural tendency toward" is from 1670s. Related: Gravitated; gravitating. The classical Latin verb was gravare "to make heavy, burden, oppress, aggravate."