Etymology
Advertisement
intone (v.1)
late 14c., entunen "sing, chant, recite, vocalize," from Old French entoner "to sing, chant" (13c.), from Medieval Latin intonare "sing according to tone," from Latin in- "in" (from PIE root *en "in") + tonus "tone," from Greek tonos, from PIE root *ten- "to stretch." Related: Intoned; intoning.
Related entries & more 
Advertisement
intone (v.2)
obsolete 17c.-18c. verb, from French entoner "thunder, roar, resound, reverberate," from Latin intonare "to thunder, resound," figuratively "to cry out vehemently," from tonare "to thunder" (see thunder (n.)). Related: Intoned; intoning.
Related entries & more 
intonate (v.1)
"to intone, recite in a singing voice," 1795, from Medieval Latin intonatus, past participle of intonare "sing according to tone" (see intone). Compare Italian intonare, French entonner. Related: Intonated; intonating.
Related entries & more 
intonation (n.)
1610s, "opening phrase of a melody," from French intonation (14c.), from Medieval Latin intonationem (nominative intonatio), noun of state from past participle stem of intonare (see intone). From 1788 as "action of intoning." Meaning "modulation of the voice in speaking, utterance of tones" is from 1791.
Related entries & more 
*ten- 
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."
Related entries & more 
Advertisement