support 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).

Proto-Indo-European root meaning "to lead, pass over." A verbal root associated with *per- (1), which forms prepositions and preverbs with the basic meaning "forward, through; in front of, before," etc.

It forms all or part of: aporia; asportation; comport; deport; disport; emporium; Euphrates; export; fare; farewell; fartlek; Ferdinand; fere; fern; ferry; firth; fjord; ford; Fuhrer; gaberdine; import; important; importune; opportune; opportunity; passport; porch; pore (n.) "minute opening;" port (n.1) "harbor;" port (n.2) "gateway, entrance;" port (n.3) "bearing, mien;" port (v.) "to carry;" portable; portage; portal; portcullis; porter (n.1) "person who carries;" porter (n.2) "doorkeeper, janitor;" portfolio; portico; portiere; purport; practical; rapport; report; sport; support; transport; warfare; wayfarer; welfare.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit parayati "carries over;" Greek poros "journey, passage, way," peirein "to pierce, pass through, run through;" Latin portare "to carry," porta "gate, door," portus "port, harbor," originally "entrance, passage," peritus "experienced;" Avestan peretush "passage, ford, bridge;" Armenian hordan "go forward;" Old Welsh rit, Welsh rhyd "ford;" Old Church Slavonic pariti "to fly;" Old English faran "to go, journey," Old Norse fjörðr "inlet, estuary."