subdivide (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).

late 14c., divisioun, "act of separating into parts, portions, or shares; a part separated or distinguished from the rest; state of being at variance in sentiment or interest," from Old French division and directly from Latin divisionem (nominative divisio), noun of action from past-participle stem of dividere "to divide" (see divide (v.)).

Military sense "portion of an army, fleet, or ship's company" is from 1590s. Mathematical sense of "operation inverse to multiplication" is from late 14c. The mathematical division sign supposedly was invented by British mathematician John Pell (1611-1685) who taught at Cambridge and Amsterdam.

early 15c., "process of dividing into smaller parts;" mid-15c., "portion of land that has been divided," noun of action from subdivide. Sense of "plot of land broken into lots for housing development" is from 1911.