How do you spell Ague

Available Definitions:
1)  n. - An acute fever.
2)  n. - An intermittent fever, attended by alternate cold and hot fits.
3)  n. - The cold fit or rigor of the intermittent fever; as, fever and ague.
4)  n. - A chill, or state of shaking, as with cold.
5)  v. t. - To strike with an ague, or with a cold fit.