Sentence:  So be neither diffuse with damp and slippery words nor blunt the edge of your discourse by <WSD>abruptness</WSD> of style. Study in particular the purest period of style, that those who move only to Ciceronian rhythm call you not a Celt. 
Meaning of the word marked with <WSD> tags:  Suddenness; unceremonious haste or vehemence. (First attested in the early 17th century.)<ref name=SOED/>