The word "un-lash" can be defined as the act of relieving or removing a lash, which may refer to a whip, a stroke, or a lash of hair. The antonyms for "un-lash" can be entangle, knot, tie, or lash. Entangle refers to the act of becoming twisted together, which is the opposite of untying or disentangling. Knot is a tight, hard knot, which can be the opposite of loosen or untie. Tie is the simplest antonym, meaning to fasten or bind, which is opposite to remove or release. Lash refers to the fastening or securing of something with a cord or rope, whereas unlashing is the act of releasing or freeing it.