The phrase 'set afoot' means to initiate or start something. Some antonyms for 'set afoot' include halt, stop, cease, and end. These words convey a sense of putting an end to an activity, rather than a beginning. Other antonyms for 'set afoot' are finish, conclude, and wrap up, which suggest that a project or activity has reached its completion. Some additional antonyms for 'set afoot' are interrupt, discontinue, and suspend, which imply a pause or an interruption in a process. Antonyms for 'set afoot' can vary depending on the context, but all suggest actions that have an opposite effect to initiating or commencing something.