What is the meaning of Ague?

An acute fever.

An intermittent fever, attended by alternate cold and hot fits.

The cold fit or rigor of an intermittent fever.

A chill, or state of shaking, as with cold.

Malaria.

To strike with an ague, or with a cold fit.

feather

fur

inflection of aguar:

1. first/third-person singular present subjunctive
2. third-person singular imperative

first/third-person singular present subjunctive

third-person singular imperative

ague (acute fever)

Source: wiktionary.org