from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Chemical isomerism characterized by relatively easy interconversion of isomeric forms in equilibrium.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A form of isomerism in which a dynamic equilibrium between multiple isomers exists, such as that between an enol and a ketone.
from the GNU version of the Collaborative International Dictionary of English
- 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.
from The Century Dictionary and Cyclopedia
- n. In organic chemistry, the phenomenon exhibited by certain compounds of reacting as if they possessed two different constitutions, that is, as if they consisted of two substances each structurally different from the other. For example, many compounds containing the group -CH2CO- behave as ketones toward some reagents, but act toward others as if they were unsaturated alcohols, -CH: COH-. In many cases both forms can be isolated.
tauto- + (iso)merism.(American Heritage® Dictionary of the English Language, Fourth Edition)