hiero-

hiero-

or hier-pref. Sacred; holy: hierology.
[Greek, from hieros, holy; see eis- in Indo-European roots.]

hiero-

or before a vowel

hier-

combining formholy or divine: hierocracy; hierarchy. [from Greek, from hieros]

hiero-

a combining form meaning “sacred,” “priestly”: hierocracy. Also, esp. before a vowel, hier-. [< Greek, comb. form of hierós]