What does "ague" mean?

Additional senses

1. 2.The cold fit or rigor of the intermittent fever; as, fever and ague.
2. 3.A chill, or state of shaking, as with cold. Dryden. Ague cake, an enlargement of the spleen produced by ague. -- Ague drop, a solution of the arsenite of potassa used for ague. -- Ague fit, a fit of the ague. Shak. -- Ague spell, a spell or charm against ague. Gay. -- Ague tree, the sassafras, -- sometimes so called from the use of its root formerly, in cases of ague. [Obs.]
3. 4.To strike with an ague, or with a cold fit. Heywood.