"public performer," 1530s, agent noun from entertain .

1530s, "provision for support of a retainer; manner of social behavior," now obsolete, along with other 16c. senses; from entertain + -ment . Meaning "the amusement of someone" is from 1610s; sense of "that which entertains" is from 1650s; that of "public performance or display meant to amuse" is from 1727.

word-forming element used freely in English, "between, among, during," from Latin inter (prep., adv.) "among, between, betwixt, in the midst of" (also used extensively as a prefix), from PIE *enter "between, among" (source also of Sanskrit antar , Old Persian antar "among, between," Greek entera (plural) "intestines," Old Irish eter , Old Welsh ithr "among, between," Gothic undar , Old English under "under"), a comparative of root *en "in."

A living prefix in English from 15c. and used with Germanic as well as Latinate words. Spelled entre- in French; most words borrowed into English in that form were re-spelled 16c. to conform with Latin except entertain , enterprise . In Latin, spelling shifted to intel- before -l- , hence intelligence , etc.

Proto-Indo-European root meaning "to stretch," with derivatives meaning "something stretched, a string; thin."

It forms all or part of: abstain ; abstention ; abstinence ; abstinent ; atelectasis ; attend ; attenuate ; attenuation ; baritone ; catatonia ; catatonic ; contain ; contend ; continue ; detain ; detente ; detention ; diatonic ; distend ; entertain ; extend ; extenuate ; hypotenuse ; hypotonia ; intend ; intone (v.1) "to sing, chant;" isotonic ; lieutenant ; locum-tenens ; maintain ; monotony ; neoteny ; obtain ; ostensible ; peritoneum ; pertain ; pertinacious ; portend ; pretend ; rein ; retain ; retinue ; sitar ; subtend ; sustain ; tantra ; telangiectasia ; temple (n.1) "building for worship;" temple (n.2) "flattened area on either side of the forehead;" temporal ; tenable ; tenacious ; tenacity ; tenant ; tend (v.1) "to incline, to move in a certain direction;" tendency ; tender (adj.) "soft, easily injured;" tender (v.) "to offer formally;" tendon ; tendril ; tenement ; tenesmus ; tenet ; tennis ; tenon ; tenor ; tense (adj.) "stretched tight;" tensile ; tension ; tensor ; tent (n.) "portable shelter;" tenterhooks ; tenuous ; tenure ; tetanus ; thin ; tone ; tonic .

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit tantram "loom," tanoti "stretches, lasts," tanuh "thin," literally "stretched out;" Persian tar "string;" Lithuanian tankus "compact," i.e. "tightened;" Greek teinein "to stretch," tasis "a stretching, tension," tenos "sinew," tetanos "stiff, rigid," tonos "string," hence "sound, pitch;" Latin tenere "to hold, grasp, keep, have possession, maintain," tendere "to stretch," tenuis "thin, rare, fine;" Old Church Slavonic tento "cord;" Old English þynne "thin."