Lexical Definition

‎ἄδολος‎ ádolos (ad'-ol-os) pure ^G:A
from ‎Α‎ (as a negative particle)

sincere.

• and ‎δόλος‎
• undeceitful, i.e. (figuratively) unadulterated

Abbott-Smith

* ἄδολος, -ον,
1. guileless (Pind., Thuc).
2. Of liquids (Æsch., Eur., and late prose writers), genuine, pure (in π. and in MGr. of wine, also of corn: MM, VGT, s.v.; Milligan, NTD, 77): of milk, metaph., I Pe 2:2.†
SYN.: ἀκέραιος (q.v.), ἄκακος, ἁπλοῦς.

Abbott-Smith References

Liddell-Scott-Jones

ἄδολος, ον,

guileless, honest, σοφία[Refs 5th c.BC+]; in Attic dialectespecially of treaties, ἄ. εἰράνα[Refs 5th c.BC+]adverb, frequently in the phrase ἀδόλως καὶ δικαίως without fraud or covin, [Refs 5th c.BC+]; ἀδολώτερον λέγεσθαι, opposed to πιστότερον, [Refs 5th c.BC+]:— also, genuinely, truly, τεθνάκην ἀ. θέλω[Refs 7th c.BC+]

__II unadulterated, genuine, χρίματος ἀδόλοισι παρηγορίαις[Refs 4th c.BC+]; χρυσός Eupolem. cited in [Refs 1st c.BC+]; σῖτος, πυρός, [Refs] pure, [NT+5th c.BC+]
__II.2 unpretentious, [Refs 1st c.AD+]

_{LSJ Scripture Refs: 1Pet.2.2}