deficiency in amount, force, power, competence, or fitness; inadequacy

insufficiency of supplies.

an instance of this.

inability of an organ or other part of the body to function normally

cardiac insufficiency.

noun

defect , deficiency , deficit , inadequacy , lack , paucity , poverty , scantiness , scantness , scarceness , scarcity , shortcoming , shortfall , underage , dearth , inability , incompetency

adjective

deficient , incomplete , insufficient