One that tells, relates or communicates the knowledge of something.

One who numbers.

In the exchequer of England, there are four officers called tellers, whose business is to receive all moneys due to the crown, and throw down a bill through a pipe into the tally-court, where it is received by the auditor’s clerks, who write the words of the bill on a tally, and deliver it to be entered by the clerk of the pell. The tally is then split by the two deputy chamberlains, who have their seals, and while the senior deputy reads the one part, the junior examines the other with the other two clerks.