a combining form meaning “shining,” “appearing, seeming,” used in the formation of compound words: phenocryst.
a combining form used in the names of chemical compounds that contain phenol or the phenyl group, are related to aromatic compounds, or derive from benzene: phenobarbital.


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Also especially before a vowel, phen-.

Origin of pheno-

< New Latin phaeno- < Greek phaino- shining, combining form of phaínein to shine, appear; in chemical senses, used orig. with reference to products from the manufacture of illuminating gas Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

British Dictionary definitions for pheno-


before a vowel phen-

combining form

showing or manifestingphenotype
indicating that a molecule contains benzene ringsphenobarbital

Word Origin for pheno-

from Greek phaino- shining, from phainein to show; its use in a chemical sense is exemplified in phenol, so called because originally prepared from illuminating gas
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for pheno-



Showing; displaying:phenotype.
Relating to or derived from benzene:phenol.
Containing phenyl:phenothiazine.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.