1 [intransitive always + adverb/preposition, transitive]
to walk first in one direction and then in another many times, especially because you are nervous:
I found Mark at the hospital, pacing restlessly up and down.
pace the floor/room
Sam stood up and paced the floor, deep in thought.
to control the speed that you move at in a race, so that you still have energy left near the end:
Nicky paced herself and came through the ranks to win.
to organize your life and activities so that you do not have too much to do:
You need to pace yourself and decide which tasks are the most important.
3 [transitive] also pace something ↔ off, pace something ↔ outTM
to measure a distance by walking across it with steps of equal length:
The director paced out the length of the stage.