[ hem-ee-as-i-tal ]
/ ˌhɛm iˈæs ɪˌtæl /


any of the class of organic chemical compounds having the general formula RCH(OH)OR, where R is an organic group.

Origin of hemiacetal

First recorded in 1890–95; hemi- + acetal
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Medicine definitions for hemiacetal


[ hĕm′ē-ăsĭ-tăl′ ]


Any of a class of compounds containing an alkyl group, especially when formed as intermediates during the preparation of acetals from aldehydes or ketones.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.