phen-
1.
variant of
pheno-
especially before a vowel:
phenazine.
British Dictionary definitions for
phen-
pheno-
combining form
1.
showing or manifesting:
phenotype
2.
indicating that a molecule contains benzene rings:
phenobarbital
Word Origin
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