on one’s feet—(also: on one’s legs)
1. standing up while working:
- He’s on his feet all day at work, and he falls asleep in his chair as soon as he gets home.
2. getting up (to speak, etc.):
- Gavin had slept armed and was on his feet at once.
3. recovered after an illness:
- It’s good to see you back on your feet again.
4. (in the phrase “think on one’s feet”) react without much deliberation:
- The ability to think on one’s feet, organize one’s thoughts and articulate them is critical.
Note: The expression does not correlate in meaning with the phrase on foot—
1. walking rather than using transport:
- The car wouldn’t start that day so we came on foot.
2. moving; in motion:
- Though he got very close to his game, they were on foot before he saw them.
3. in progress; taking place:
- It was also possible that some love intrigue was on foot.
4. being planned:
- The reporter also said that a civil rights demonstration was on foot.
out on one’s feet—
1. (of a boxer) dazed or barely conscious, although still in a standing position:
- For God’s sake keep an eye on John! He’s out on his feet but doesn’t realize it!
2. (coll.) barely able to stand; totally fatigued:
- You’re ill…. You may not know it, but you’re out on your feet.