ἅλας (T, ἅλα), -ατος, τό, late form of cl. ἅλς, -ος, ὁ (MM, VGT, see word), [in LXX chiefly for מְלַח ;] salt, lit, and fig.: Refs Mat.5:13, Mrk.9:50 Luk.14:34; like cl. ἅλες, wit, of wisdom and grace in speech: Col.4:6.† (AS)
Thayer:
1) salt with which food is seasoned and sacrifices are sprinkled 2) those kinds of saline matter used to fertilise arable land 3) salt is a symbol of lasting concord, because it protects food from putrefaction and preserves it unchanged. Accordingly, in the solemn ratification of compacts, the orientals were, and are to this day, accustomed to partake of salt together 4) wisdom and grace exhibited in speech
ἅλας
halas
hal'-as
From G251; salt; figuratively prudence