on end—
1. in an upright position; standing erect:
- The houses gave to the outskirts of Paris an odd affinity to a city built of dominoes set on end.
2. (of time) continually; without intermission:
- For hours on end we were subjected to continuous attacks from bombers.
on the end —(also: at the end) in the farthest part of smth.:
- An electric toothbrush is not very different in principle from an ordinary toothbrush. You still have a stick with a brush on the end.