IPA: /ˈmɛltər/
KK: /ˈmɛltər/
A person or device that causes something to become liquid by heating it.
The melter in the factory was responsible for turning solid metal into molten form.
Melter → It is formed from "melt" (from Old English "meltan", meaning to cause to become liquid) and "-er" (meaning a person who). A melter is a person or thing that causes something to become liquid.
Think of someone who 'causes to become liquid' — that's what a melter does.