1: ἀγράμματος
(Strong's #62 — Adjective — agrammatos — ag-ram-mat-os )

lit., "unlettered" (grammata, "letters:" grapho, "to write"), Acts 4:13 , is explained by Grimm-Thayer as meaning "unversed in the learning of the Jewish schools;" in the papyri, however, it occurs very frequently in a formula used by one who signs for another who cannot write, which suggests that the rulers, elders and scribes regarded the Apostles as "unlettered" (Moulton and Milligan).

2: ἀμαθής
(Strong's #261 — Adjective — amathes — am-ath-ace' )

"unlearned" (manthano, "to learn"), is translated "unlearned" in 2—Peter 3:16 , AV (RV, "ignorant").

3: ἀπαίδευτος
(Strong's #521 — Adjective — apaideutos — ap-ah'ee-dyoo-tos )

"uninstructed" (paideuo, "to train, teach"), is translated "unlearned" in 2—Timothy 2:23 , AV (RV, "ignorant").

1—Corinthians 14:16,23,24IGNORANT