descend (v.)

late 14c., scannen, "to mark off verse in metric feet, analyze verse according to its meter," from Late Latin scandere "to scan verse," originally, in classical Latin, "to climb, rise, mount" (the connecting notion is of the rising and falling rhythm of poetry), from PIE *skand- "to spring, leap, climb" (source also of Sanskrit skandati "hastens, leaps, jumps;" Greek skandalon "stumbling block;" Middle Irish sescaind "he sprang, jumped," sceinm "a bound, jump").

English lost the classical -d- probably by confusion with suffix -ed (compare lawn (n.1)). Intransitive meaning "follow or agree with the rules of meter" is by 1857. The sense of "look at point by point, examine minutely (as one does when counting metrical feet in poetry)" is recorded by 1540s. New technology brought the meaning "systematically pass over with a scanner," especially to convert into a sequence of signals (1928). The (opposite) sense of "look over quickly, skim" is attested by 1926. Related: Scanned; scanning.

mid-15c. (adj.) "extending downward;" c. 1600 (n.) "an individual proceeding from an ancestor in any degree," from French descendant (13c.), present participle of descendre "to come down" (see descend).

Despite a tendency to use descendent for the adjective and descendant for the noun, descendant seems to be prevailing in all uses and appears 5 times more often than its rival in books printed since 1900. Compare dependant. In astrology, "the western horizon or cusp of the seventh house," 1680s.