counter
One who counts.
Example
“He's only 16 months, but is already a good counter – he can count to 100.”
Other meanings
A reckoner; someone who collects data by counting; an enumerator.
An object (now especially a small disc) used in counting or keeping count, or as a marker in games, etc.
“He rolled a six on the dice, so moved his counter forward six spaces.”
Example sentences
Word history
From Latin "computō".
Where this comes from
This definition is adapted from “counter” on Wiktionary, by its contributors; example sentences are from Tatoeba, credited to their authors above, published under CC BY-SA 4.0. This page is published under the same licence.