aporia (n.)

prefix meaning "not, without," from Greek a-, an- "not" (the "alpha privative"), from PIE root *ne- "not" (source also of English un-).

In words from Greek, such as abysmal, adamant, amethyst; also partly nativized as a prefix of negation (asexual, amoral, agnostic). The ancient alpha privatum, denoting want or absence.

Greek also had an alpha copulativum, a- or ha-, expressing union or likeness, which is the a- expressing "together" in acolyte, acoustic, Adelphi, etc. It is from PIE root *sem- (1) "one; as one, together with."

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."