Strong's Greek #552 - ἄπειρος, ον apeiros (without experience of)

unskillful, inexperienced

From a (as a negative particle) and peira; inexperienced, i.e. Ignorant -- unskilful.

see GREEK a

see GREEK peira

Strong's 552: ἄπειρος

ἄπειρος, ἀπειρον (πεῖρα trial, experience), inexperienced in, without experience of, with the genitive of the thing (as in Greek writings): Hebrews 5:13. ((Pindar and Herodotus down.))

Strong's Greek: 552. ἄπειρος (apeiros) — 1 Occurrence

Hebrews 5:13 - Adj-NMS
GRK: μετέχων γάλακτος ἄπειρος λόγου δικαιοσύνης
NAS: [only] of milk is not accustomed to the word
KJV: milk [is] unskilful in the word
INT: partakes of milk [is] unskilled in [the] word of righteousness