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Webster 1913 Edition
Pyroacetic
Pyrˊo-a-ce′tic
,Adj.
 [
Pyro- 
+ acetic
: cf. F. pyroacétique
.] (Chem.) 
Pertaining to, and designating, a substance (acetone) obtained by the distillation of the acetates. It is now called also 
pyroacetic ether
, and formerly was called pyroacetic spirit
.