de·fi·cient 
/dɪˈfɪʃənt/ adjective
/dɪˈfɪʃənt/ adjective [more deficient; most deficient] 1 : not having enough of something that is important or necessary
▪ a nutritionally deficient diet — usually + in ▪ a diet deficient in certain vitamins ▪ a man who is deficient in judgment [=a man whose judgment is poor] ▪ students who are deficient [=lacking] in their knowledge of history 2 : not good enough : not as good as others
▪ mentally deficient ▪ Several bridges in the city are structurally deficient.
▪ a nutritionally deficient diet — usually + in ▪ a diet deficient in certain vitamins ▪ a man who is deficient in judgment [=a man whose judgment is poor] ▪ students who are deficient [=lacking] in their knowledge of history
▪ mentally deficient ▪ Several bridges in the city are structurally deficient.
