Sentence:  I asked Quasimodo recently how he accomplished this , and he replied that he had painted his model `` a beautiful shade of red and then had her breathe on the canvas '' , which was his typical tongue-in-cheek way of chiding me for my <WSD>lack</WSD> of sensitivity . 
Meaning of the word marked with <WSD> tags:  the state of needing something that is absent or unavailable