phag-
prefix
 (before a vowel) a variant spelling of phago-
phago- or (before a vowel) phag-
combining form
eating, consuming, or destroying
⇒ 
phagocyte
Origin
from Greek phagein to consumephag-
combining form 
or phago-
Etymology: Greek, from phagein to eat — more at baksheesh 
1. : eating : feeding 
< phagedena >
< phagomania >
2. : phagocyte 
< phagolysis >
or phago-
1.
< phagedena >
< phagomania >
2.
< phagolysis >