The Collaborative International Dictionary of English v.0.48:

Alcoholometer \Al`co*hol*om"e*ter\, Alcoholmeter
\Al`co*hol"me*ter\, n. [Alcohol + -meter.] (Chem.)
   An instrument for determining the strength of spirits, with a
   scale graduated so as to indicate the percentage of pure
   alcohol, either by weight or volume. It is usually a form of
   hydrometer with a special scale.
   [1913 Webster] Alcoholometrical
   Alcoholometric