FROM STRONG’S GREEK DICTIONARY (1890)

Strong’s Greek Dictionary (1890) — public domain, printed whole.

nepios νήπιος — nay'-pee-os — from an obsolete particle ne- (implying negation) and 2031; not speaking, i.e. an infant (minor); figuratively, a simple-minded person, an immature Christian:--babe, child (+ -ish).

see GREEK for 2031