phren-

1.
variant of phreno- before a vowel:
phrenic.
British Dictionary definitions for phren-

phreno-

combining form
1.
mind or brain: phrenology
2.
of or relating to the diaphragm: phrenic
Word Origin
from Greek phrēn mind, diaphragm
phren- in Medicine

phren- pref.
Variant of phreno-.