1. (

• lack ,
• deficiency ,
• want ,

) 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" ;

2. (

• insufficiency ,
• inadequacy ,
• deficiency

) lack of an adequate quantity or number; "the inadequacy of unemployment benefits" ;