Unlashing is a term typically used to refer to the act of undoing or loosening something from its lashings. Some antonyms for the word unlashing could include terms like lashing, securing, binding, fastening, or tethering. These terms often denote actions that involve holding something in place, rather than freeing it or letting it go. For example, if you were to secure something with a rope or a strap, you would be doing the opposite of unlashing it. Similarly, terms like binding, fastening, or tethering all suggest a sense of restriction or confinement, while unlashing implies a sense of release or freedom.