Sentence:  "Well," I says, "I cal'late a body could get used to Tophet if he stayed there long enough." She flared up; the least <WSD>mite</WSD> of a slam at Doctor Wool was enough to set her going. 
Meaning of the word marked with <WSD> tags:  (sometimes used adverbially) Anything very small; a minute object; a very little quantity or particle