Who were Morwe and Nurwe in Tolkien's legendarium?

Answer 1

They were conceived as the leaders of the Avari, "the Unwilling", those Elves who were unwilling to go on the Great March to Aman. It seems as if the two characters - about whom nothing else is known other than their names - were later abandoned.

Answer 2

Morwe and Nurwe were the two spouses of Nienna, a Vala known for her grief and compassion. They are rarely mentioned in Tolkien's works, and not much is known about them other than their relationship to Nienna.