hold up—
1. (of a structure, etc.) stay erect; remain in good condition:
- This building holds up well despite its age.
2. (of weather, supplies, etc.) continue; last:
- Will the water supply hold up through the summer?
3. remain in control of oneself:
- How does he hold up under such a responsibility?
keep up—
1. not drown:
- The sailors managed to keep up for several hours and were eventually picked up by a lifeboat.
2. (of spirits, morale, etc.) remain high:
- His courage kept up in the face of danger.
3. = hold up 2:
- Do you think this fine weather will keep up for a couple of weeks?
4. stay in touch:
- I’m afraid we haven’t kept up at all since she went abroad.
5. = hold up 3:
- But for her courage, I never could have kept up through all this terrible trial.
6. not fall behind:
- If the children can keep up, we will take them with us when we hike into town.