naphthenic acid
nounDefinition of naphthenic acid
: any of numerous chiefly monocarboxylic acids derived from naphthenes and obtained from naphthene-base and asphalt-base petroleums
usually
: a commercial viscous liquid mixture of such acids used especially in the form of salts (as copper naphthenate) as paint driers and preservatives for wood and textiles — see metallic soap