To force someone to stay active, alert, and focused on something or someone. Having two kids under age five sure keeps me on my toes!
COMMON If someone or something keeps you on your toes, they stop you being lazy or relaxed and force you to be ready for anything that might happen. She kept us on our toes right from the moment she took command. His lively campaign has kept opposition parties on their toes for months. It's always good to have a little bit of change in your job, because it keeps you on your toes, doesn't it?
(informal) make sure that somebody is ready to deal with anything that might happen by doing things that they are not expecting: Regular surprise visits help to keep the staff on their toes. ♢ This job really keeps me on my toes.