This would be for a sword.
It glows gently with an inner light when drawn, sufficient for elvish eyes to see in darkness, and its light seems to softly illuminate with Varda’s starlight that which is hidden. Its light does not warn of evil folk nearby, as so many of the fell swords of the elves do, rather its bearer sees more truly that which they gaze upon. It feels light to the hand that bears it, and rings clearly, as if wishing to sing, when it is drawn. Its blade bites deeply upon the servants of the Morgoth (and thus Sauron).
Relevant words seem to be:
Huinë gloom, deep shadow, night shade Fuinë deep shadow Lumbë gloom, shadow Yaru gloom, blight Hyando cleaver, hewer
Relevant example usage:
sangahyando = throng-cleaver
Yaruhyando seems like a good match for its name. Yaru with its connotation of both gloom and the blight of evil, and hyando for the meaning of cleaver.