万歳

Etymology 1
Shift in reading from below, keeping the older goon reading for the second character and adopting the relatively newer kan'on reading for the first character.

Noun

 * 1) an extremely long period of time
 * 2)  raising ones hands
 * 3)  business troubles, bankruptcy
 * 1)  raising ones hands
 * 2)  business troubles, bankruptcy

Etymology 2
From. The kan'on, so likely a later borrowing.

Noun

 * 1) an extremely long period of time
 * 2) long life and glory
 * 3) death

Etymology 3
From. The goon, so likely the initial borrowing.

Noun

 * 1) an extremely long period of time
 * 2) a song and dance to celebrate a new year
 * 3) a song sung to celebrate a new year
 * 1) a song sung to celebrate a new year