Definitions
1.nounA defect or failing; moral or spiritual degeneracy.
2.nounA deficiency or need (of something desirable or necessary); an absence, want.
3.verbTo be without, to need, to require."My life lacks excitement."
4.verbTo be short (of or for something)."He'll never lack for company while he's got all that money."
5.verbTo be in want.
6.verbTo see the deficiency in (someone or something); to find fault with, to malign, reproach.