late 15c., "fountain, stream," of uncertain origin, probably from Middle French sourge-, stem of sourdre "to rise, swell," from Latin surgere "to rise, arise, get up, mount up, ascend; attack," contraction of surrigere, from assimilated form of sub "up from below" (see sub-) + regere "to keep straight, guide" (from PIE root *reg- "move in a straight line," with derivatives meaning "to direct in a straight line," thus "to lead, rule"). Meaning "high, rolling swell of water" is from 1520s; figurative sense of "excited rising up" (as of feelings) is from 1510s.
1510s, "to rise and fall," from surge (n.), or from Middle French surgir "rise, ride (as a ship does a wave), spring up, arrive." Meaning "rise high and roll forcefully" is from 1560s. Related: Surged; surging.