The antonyms for the word "demount" are mount, install, fix, attach, and secure. "Demount" means to remove or take apart a mounted or attached object, while its antonyms refer to the act of putting something in place or affixing it in a stable position. Mounting a picture frame on a wall, installing a new light fixture, fixing a bike seat, attaching a document to an email, and securing a fence panel to a post are all examples of activities that involve the antonyms of demount. These words are essential in expressing the opposite action or contrasting ideas related to demounting.