From Longman Dictionary of Contemporary Englishon your feeton your feeta)STANDto be standing for a long time without having time to sit downThe worst thing about working in the shop is that you’re on your feet all day. → dead on your feetat dead1(8)b)STANDto be standing upAs soon as the bell rang the class were on their feet and out of the door.c)to feel better again after being ill and in bedWe’ll soon have you on your feet again. →foot
Examples from the Corpus
on your feet• She'd been on her feet all morning without once sitting down.• You go. I've been on my feet all day, and I need a rest.• The crowd was on its feet.• Daley was on his feet, his armswaving, his mouth working.• He was on his feet, gathering up books from his desk.• He was on his feet, holding out his hand to Nick who went to him and took it trustingly.• I was on my feet in the darkness, dressing quietly.• A correspondent from the New York Times was on his feet.• A socialistyouth was on his feet, roaring with all the force and outrage of his years.• The ones she had just knocked down were on their feet again, hopping on the steps around her.