Vanity

Does not usually denote, in Scripture, self-conceit or personal pride, 2 Peter 2:18, but sometimes emptiness and fruitlessness, Job 7:3 Psalms 144:4 Ecclesiastes 1:1-18. It often denotes wickedness, particularly falsehood, Deuteronomy 32:21 Psalms 4:2 24:4 119:37, and sometimes idols and idol-worship, 2 Kings 17:15 Jeremiah 2:5 18:15 Jonah 2:8. Compare Paul’s expression, "they turned the truth of God into a lie," Romans 1:25. "In vain," in the second commandment, Exodus 20:7, is unnecessarily and irreverently. "Vain men," 2 Samuel 6:20 2 Chronicles 13:7, are dissolute and worthless fellows.

Source: ATS Bible Dictionary
Vanity

VAN'ITY, n. L. vanitas, from vanus, vain.

1. Emptiness; want of substance to satisfy desire; uncertainty; inanity.

Vanity of vanities, said the preacher; all is vanity. Eccles. 1.

2. Fruitless desire or endeavor.

Vanity possesseth many who are desirous to know the certainty of things to come.

3. Trifling labor that produces no good.
4. Emptiness; untruth

Here I may well show the vanity of what is reported in the story of Walsingham.

5. Empty pleasure; vain pursuit; idle show; unsubstantial enjoyment.

Sin with vanity had fill'd the works of men.

Think not when woman's transient breath is fled, that all her vanities at once are dead; succeeding vanities she still regards.

6. Ostentation; arrogance.
7. Inflation of mind upon slight grounds; empty pride, inspired by an overweening conceit of one's personal attainments or decorations. Fops cannot be cured of their vanity.

Vanity is the food of fools.

No man sympathizes with the sorrows of vanity.

Source: King James Dictionary