succumb v.

word-forming element meaning "under, beneath; behind; from under; resulting from further division," from Latin preposition sub "under, below, beneath, at the foot of," also "close to, up to, towards;" of time, "within, during;" figuratively "subject to, in the power of;" also "a little, somewhat" (as in sub-horridus "somewhat rough"), from PIE *(s)up- (perhaps representing *ex-upo-), a variant form of the root *upo "under," also "up from under." The Latin word also was used as a prefix and in various combinations.

In Latin assimilated to following -c-, -f-, -g-, -p-, and often -r- and -m-. In Old French the prefix appears in the full Latin form only "in learned adoptions of old Latin compounds" [OED], and in popular use it was represented by sous-, sou-; as in French souvenir from Latin subvenire, souscrire (Old French souzescrire) from subscribere, etc.

The original meaning is now obscured in many words from Latin (suggest, suspect, subject, etc.). The prefix is active in Modern English, sometimes meaning "subordinate" (as in subcontractor); "inferior" (17c., as in subhuman); "smaller" (18c.); "a part or division of" (c. 1800, as in subcontinent).

mid-15c., "bedroom, bedchamber," from Latin cubiculum "bedroom," from cubare "to lie down," which is perhaps from a PIE *kub-, with cognates in Middle Welsh kyscu, Middle Cornish koska, Middle Breton cousquet "to sleep," but de Vaan regards the PIE origin of the Latin word as "uncertain." Compare cubit.

Obsolete from 16c. but revived by 1858 for "dormitory sleeping compartment," especially in an English public school. The sense of "any partitioned space" (such as a library carrel or, later, office work station) is attested by 1926. Related: Cubicular.

Proto-Indo-European root meaning "under," also "up from under," hence "over."

It forms all or part of: above; assume; Aufklarung; eave; eavesdropper; hyphen; hypo-; hypochondria; hypocrisy; hypotenuse; hypothalamus; hypothesis; hypsi-; hypso-; opal; open; oft; often; resuscitate; somber; souffle; source; soutane; souvenir; sub-; subject; sublime; subpoena; substance; subterfuge; subtle; suburb; succeed; succinct; succor; succubus; succumb; sudden; suffer; sufficient; suffix; suffrage; suggestion; summon; supine; supple; supply; support; suppose; surge; suspect; suspend; sustain; up; up-; Upanishad; uproar; valet; varlet; vassal.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit upa "near, under, up to, on," Greek hypo "under," Latin sub "under, below," Gothic iup, Old Norse, Old English upp "up, upward," Hittite up-zi "rises."