Enchant Weapon - Winter's Might

Enchant Weapon - Winter's Might permanently enchants a weapon to increase the spell power of frost spells by 7. It does not create a glowing effect on the weapon.

This enchantment was introduced during the 2005 Christmas world event.

Enchanting Level Required: 190

Source
is a possible reward from quests related to the Feast of Winter Veil which occurs in December. Specifically, it is one of the possible rewards for the quest.