deficient
adj.not having enough of something that is necessary, like a vitamin or a specific skill.
adj.lacking in a necessary quality, element, or amount. Often used in medical or technical contexts to describe a shortage that prevents proper functioning.
“His diet is deficient in vitamin C.”
“The inspection found that the building's fire safety measures were deficient and required immediate upgrades.”
“While the theory was elegant in its simplicity, it proved deficient when applied to real-world data that accounted for environmental variables the researchers had initially ignored.”
Commonly followed by the preposition 'in'.
The adjective 'deficient' collocations with 'in' rather than 'of' when specifying what is lacking.
“After trying to persuade her to avoid divorce, the governor later comments that women are "mindless" and "deficient in intellect", to laughter from the male officials, bodyguards and elders around him.”
“When the animals could freely choose between standard chow and soybean oil, the OPA1-deficient mice consumed more fat and gained additional weight.”
From Latin deficiens, present participle of deficere (“to lack, fail, be wanting”); see defect.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.