Lexical Definition

‎ἄζυμος‎ ázymos (ad'-zoo-mos) unleavened ^G:A
from ‎Α‎ (as a negative particle) and ‎ζύμη‎

unleavened (bread).

• unleavened, i.e. (figuratively) uncorrupted
• (in the neutral plural) specially (by implication) the Passover week

Abbott-Smith

ἄζυμος, -ον (< ζύμη), [in LXX for מָצָּה; τὰ ἄ. (sc. λάγανα, cakes) = הַמָצָּה;]
unleavened: ἡ ἑορτὴ τῶν ἄ. (הַג הַמָצָּה), the paschal feast (also called τὰ ἄ., Mk 14:1), Lk 22:1; ἡμέρα τῶν ἄ., Mt 26:17, Mk 14:12, Lk 22:7; ἡμέραι, Ac 12:3 20:6. Fig., of Christians, free from corruption: I Co 5:7; exhorted to keep festival, ἐν ἀζύμοις (sc. ἄρτοις, λάγανοις, or, indefinitely, "unleavened elements"), I Co 5:8 (Cremer, 724).†

Abbott-Smith References

Liddell-Scott-Jones

ἄζυμος, ον,

without process of fermentation, [Refs 5th c.BC+]:—of bread, unleavened, ἄρτος[Refs 5th c.BC+]; ἄρτους ἀ., ἄζυμα λάγανα, [LXX]the feast of unleavened cakes, [NT]; ἡ ἑορτὴ τῶν ἀ. [LXX+NT]

_{LSJ Scripture Refs: LXX.Exod.29.2 ☩ LXX.Lev.2.4 ☩ LXX.Exod.12.15 ☩ Mark.14.1 ☩ LXX.2Chr.8.13 ☩ Luke.22.1}