aha is a noun meaning "rage" in Quenya.
In the First Age, aha was pronounced acha.
TengwaTengwar alphabet. In Westron it was called Shé and it had the value of sh in Mannish modes.
The original name of Aha was Charma and in Quenya it had the value "ch". Over time the "ch" in Quenya softened to "h" at the beginning of words and the letter, now called Acha, was only used in the middle of words where ch still retained. Still later the "ch" sound disappeared altogether and the letter name as well became Aha.