succumb: [15] Someone who succumbs to something is etymologically ‘lying down under’ it. The word comes via Old French succomber from Latin succumbere, a compound verb formed from the prefix sub- ‘under’ and -cumbere ‘lie’. This verbal element also produced English incumbent and recumbent, and the non-nasalized version of its stem lies behind covey, incubate, incubus, and succubus. => covey, incubate, incumbent, recumbent