Easton's Bible Dictionary
The Hebrew so rendered means "a covering," because clouds cover the sky. The word is used as a symbol of the Divine presence, as indicating the splendour of that glory which it conceals (Exodus 16:10; 33:9; Numbers 11:25; 12:5; Job 22:14; Psalm 18:11). A "cloud without rain" is a proverbial saying, denoting a man who does not keep his promise (Proverbs 16:15; Isaiah 18:4; 25:5; Jude 1:12). A cloud is the figure of that which is transitory (Job 30:15; Hosea 6:4). A bright cloud is the symbolical seat of the Divine presence (Exodus 29:42, 43; 1 Kings 8:10; 2 Chronicles 5:14; Ezek. 43:4), and was called the Shechinah (q.v.). Jehovah came down upon Sinai in a cloud (Exodus 19:9); and the cloud filled the court around the tabernacle in the wilderness so that Moses could not enter it (Exodus 40:34, 35). At the dedication of the temple also the cloud "filled the house of the Lord" (1 Kings 8:10). Thus in like manner when Christ comes the second time he is described as coming "in the clouds" (Matthew 17:5; 24:30; Acts 1:9, 11). False teachers are likened unto clouds carried about with a tempest (2 Peter 2:17). The infirmities of old age, which come one after another, are compared by Solomon to "clouds returning after the rain" (Ecclesiastes 12:2). The blotting out of sins is like the sudden disappearance of threatening clouds from the sky (Isaiah 44:22).
Cloud, the pillar of, was the glory-cloud which indicated God's presence leading the ransomed people through the wilderness (Exodus 13:22; 33:9, 10). This pillar preceded the people as they marched, resting on the ark (Exodus 13:21; 40:36). By night it became a pillar of fire (Numbers 9:17-23).
Noah Webster's New International Dictionary of the English Language
1. (n.) A collection of visible vapor, or watery particles, suspended in the upper atmosphere.
2. (n.) A mass or volume of smoke, or flying dust, resembling vapor.
3. (n.) A dark vein or spot on a lighter material, as in marble; hence, a blemish or defect; as, a cloud upon one's reputation; a cloud on a title.
4. (n.) That which has a dark, lowering, or threatening aspect; that which temporarily overshadows, obscures, or depresses; as, a cloud of sorrow; a cloud of war; a cloud upon the intellect.
5. (n.) A great crowd or multitude; a vast collection.
6. (n.) A large, loosely-knitted scarf, worn by women about the head.
7. (v. t.) To overspread or hide with a cloud or clouds; as, the sky is clouded.
8. (v. t.) To darken or obscure, as if by hiding or enveloping with a cloud; hence, to render gloomy or sullen.
9. (v. t.) To blacken; to sully; to stain; to tarnish; to damage; -- esp. used of reputation or character.
10. (v. t.) To mark with, or darken in, veins or sports; to variegate with colors; as, to cloud yarn.
11. (v. i.) To grow cloudy; to become obscure with clouds; -- often used with up.