Here's a breakdown:
* मेल (mel) means "match"
* मिलाने (milane) means "to match"
* वाला (wala) is a suffix indicating "one who does" or "one who is related to"
Therefore, मेल मिलाने वाला literally translates to "one who matches" or "one who is involved in matching."
You can also use विवाह कराने वाला (vivah karane wala), which means "one who arranges marriages" or "wedding arranger."