Sentence:  But when the government of Churches came into the hands of their Successours; the names were by common <WSD>usuage</WSD> (which is the best master of words) very soon appropriated, that use Episcopus to the Ecclesiasticall Government or Bishop of a diocese and a that of Presbyter to the ordinary Minister or Priests. 
Meaning of the word marked with <WSD> tags:  (usage)<ref name= "OEDJHM">Murray, J.A.H. The Compact Edition of the Oxford English Dictionary (2 vols). Publisher: Oxford University Press. 1971. (978-0198611172)</ref>