Sentence:  In the experimental animal and in man gross <WSD>deficiency</WSD> in dietary iodine causes thyroid hyperplasia , hypertrophy and increased thyroid activity ( Money , Rall and Rawson , 1952 ; Stanbury , Brownell , Riggs , Perinetti , Itoiz , and Del Castillo , 1954 ) . 
Meaning of the word marked with <WSD> tags:  the state of needing something that is absent or unavailable