Boyd’s Bible Dictionary:
(measurer). Conjointly with the sun, appointed for signs, seasons, days, months and years. Regulator of religious festivals (Gen. 1:14-18). Worship of, forbidden (Deut. 4:19). Used largely figuratively (Isa. 13:10; Matt. 24:29; Mark 13:24).
Concise Bible Dictionary:
At the creation the “lesser light” was to rule the night. Its brilliancy is seen much more in the east than in the west, and its light is more appreciated in the former, especially when the heat of the day necessitates traveling by night. The NEW MOON among the Israelites was a festival: it was watched for on the hills, and as soon as it was seen, it was ushered in by sound of trumpet (Num. 10:10; 1 Chron. 23:31; Psa. 81:3; Ezek. 45:17; Col. 2:16; compare 1 Sam. 20:5,18,24).
The Israelites were warned against worshipping the moon as well as the sun and stars (Deut. 4:19; Deut. 17:3; compare Job 31:26-28). Of Israel, in the time of Hoshea and of Manasseh it is said they worshipped “all the host of heaven” (2 Kings 17:16; 2 Kings 21:3,5). Jeremiah also states that in Judah and Jerusalem cakes were made to the QUEEN OF HEAVEN, which is commonly supposed to refer to the moon, worshipped as Astarte. Then when the residue of the people had gone into Egypt, they declared that in spite of the prophet’s warning they would burn incense to the Queen of Heaven, and pour out drink offerings unto her (Jer. 7:18; Jer. 44: 17-19,25).
There will be SIGNS IN THE MOON as well as in the sun when the time of God’s dire judgment has arrived (Joel 2:10, 31; Luke 21:25; Rev. 6:12). As a symbol the moon is used in prophecy to signify derivative authority, the sun being the supreme source of heavenly rule.
Strong’s Dictionary of Greek Words:
Meaning:
from σέλας (brilliancy; probably akin to the alternate of 138, through the idea of attractiveness); the moon