1. [n]  a mark (') placed above a vowel to indicate pronunciation
2. [n]  a fit of shivering
3. [n]  successive stages of chills and fever that is a symptom of malaria

AGUE is a 4 letter word that starts with A.

1. \A"gue\, n. [OE. agu, ague, OF. agu, F. aigu, sharp, OF.
   fem. ague, LL. (febris) acuta, a sharp, acute fever, fr. L.
   acutus sharp. See {Acute}.]
   1. An acute fever. [Obs.] ``Brenning agues.'' --P. Plowman.
   2. (Med.) An intermittent fever, attended by alternate cold
      and hot fits.
   3. The cold fit or rigor of the intermittent fever; as, fever
      and ague.
   4. 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.]
   

2. \A"gue\, v. t. [imp. & p. p. {Agued}.]
   To strike with an ague, or with a cold fit. --Heywood.
   

the translation in Lev. 26:16 (R.V., "fever") of the Hebrew word kaddah'ath, meaning "kindling", i.e., an inflammatory or burning fever. In Deut. 28:22 the word is rendered "fever."