The word "pace" is used when describing speed and movement.
The boat is moving at a very quick pace.
This line is moving at a slow pace.
The pace of the runners on the track helped the first-place finisher break a world record.
The company is producing products at a furious pace. (furious = very quick)
In the next set of sentences, "pace" is a verb that means to observe or monitor one’s speed. Notice that a reflexive pronoun is often used in this instance.
I’m trying to pace myself. (I’m monitoring my speed.)
Don’t run too fast. Try to pace yourself.
He’s pacing himself.
If we walk too fast we’ll get tired. Let’s pace ourselves.
They don’t want to spend all of their money on the first few days of their vacation. They’re pacing themselves.
When used as a verb, "pace" also means to walk back and forth. Pacing may indicate that a person is nervous or worried about something:
The man paced up and down the hallway as he waited for an update from the doctor on his wife’s condition.
Someone is pacing in front of the building.
The dog is pacing in front of the fence.
Why are you pacing? Are you nervous?
When something or someone moves slowly, we say that it moves at a snail’s pace. In other words, it moves very slowly.