How do you spell Intonation

Available Definitions:
1)  n. - A thundering; thunder.
2)  n. - The act of sounding the tones of the musical scale.
3)  n. - Singing or playing in good tune or otherwise; as, her intonation was false.
4)  n. - Reciting in a musical prolonged tone; intonating, or singing of the opening phrase of a plain-chant, psalm, or canticle by a single voice, as of a priest. See Intone , v. t.