adjective🔗ShareLacking something essential; often construed with in."The student's knowledge of grammar was deficient, making it hard for her to complete the writing assignments. "conditionqualityChat with AIVocabulary GamePractice Reading
adjective🔗ShareInsufficient or inadequate in amount."The student's knowledge of fractions was deficient, causing problems with the math assignments. "amountqualityconditionChat with AIVocabulary GamePractice Reading
adjective🔗ShareOf a number n, Having the sum of divisors σ(n)<2n, or, equivalently, the sum of proper divisors (or aliquot sum) s(n)"The number 10 is considered deficient because the sum of its proper divisors (1, 2, and 5) is 8, which is less than 10. "mathnumberChat with AIVocabulary GamePractice Reading