TAUTOG n.
An edible labroid fish (Haitula onitis, or Tautoga onitis) of the Atlantic coast of the United States. When adult it is nearly black, more or less irregularly barred, with greenish gray. Called also blackfish, oyster fish, salt-water chub, and moll. [Written also tautaug.]
TAUTOMERISM n.
The condition, quality, or relation of metameric substances, or their respective derivatives, which are more or less interchangeable, according as one form or the other is the more stable. It is a special case of metamerism; thus, the lactam and the lactim compounds exhibit tautomerism.