CLERK (clericus), a word formerly used to signify a learned man, or man of letters. The word comes from the Greek κλῆρος, used for clergy; but more properly signifying lot or heritage, in regard the lot and portion of clerks or ecclesiastics is to serve God. Accordingly, clerus was at first used to signify those who had a particular attachment to the service of God. The origin of the expression is derived from the Old Testament, where the tribe of Levi is called the lot, heritage, κλῆρος; and God is reciprocally called their portion; by reason that tribe was consecrated to the service of God, and lived on the offerings made to God, without any other settled provision as the rest had.
Thus, Pasquier observes, the officers of the counts (comites) were anciently created under the title of clerks of accounts; and secretaries of state were called, clerks of the secret. So, clericus domini regis, in the time of Edward I. was Englished, the king's secretary, or clerk of his council. The term was applied indifferently to all who made any profession of learning; or who knew how to manage the pen: though originally it was appropriated to ecclesiastics. As the nobility and gentry were usually brought up to the exercise of arms, there was none but the clergy left to cultivate the sciences: hence, as it was the clergy alone who made any profession of letters, a very learned man came to be called a great clerk; and a stupid ignorant man, a bad clerk.