IPA: /ˈmɛʒər/
KK: /ˈmɛʒər/
A person or device that determines the size, amount, or degree of something by using a specific standard or unit.
The measurer used a tape to find the length of the room.
Measurer → It is formed from "measure" (from Old French *mesurer*, meaning to determine the extent or quantity of something) and "-er" (meaning a person who). A measurer is a person who determines or assesses the extent or quantity of something.
Think of someone who 'determines' ('measure') the 'extent' of something — that's why a measurer is a person who measures.