Welsh:
* MEH-lin: This is the most common pronunciation in Welsh, with the "y" pronounced like the "i" in "machine."
Other possibilities:
* MEH-lin: This pronunciation is also sometimes used for the name, even if it's not of Welsh origin.
* MEH-luhn: This pronunciation emphasizes the "l" sound, which is sometimes used in English for names with a similar spelling.
Ultimately, the best way to know how to pronounce "Melyn" is to ask the person who has the name how they prefer it.