Meaning

verb utter monotonously and repetitively and rhythmically

verb recite with musical intonation; recite as a chant or a psalm

verb speak carefully, as with rising and falling pitch or in a particular tone

originFrom Middle English entune, entone, from Old French entoner, from Medieval Latin intonō, from in- (inchoative prefix) + tonus (“pitch, tone”) + -ō (verb-forming suffix); doublet of intonate. Cognate with French entonner, Italian intonare.

Etymology from Wiktionary, CC BY-SA 3.0