the state of needing something that is absent or unavailable
"there is a serious lack of insight into the problem"
"water is the critical deficiency in desert regions"
"for want of a nail the shoe was lost"
A defect or failing; moral or spiritual degeneracy.
In plain English: A lack is when there isn't enough of something you need.
"The main issue with the new plan is a complete lack of funding."
Usage: Use "lack" to refer to an absence or shortage of something necessary, such as funds or resources. Do not use it to describe a moral failing or personal defect.
To be without, to need, to require.
"The project failed because we lacked a clear leader to guide our decisions."
In plain English: To lack something means to not have it at all.
"The project failed because we lacked enough funding to finish on time."
Usage: Use "lack" only when something is completely missing or absent, not when you simply have a small amount of it. For example, say "we lack time" if there is none left, but avoid saying "I lack some patience" when you just need more.
The word "lack" comes from Old English, where it originally meant a deficiency or want. It traveled into modern English with this same meaning of not having enough of something.