to make something stay at a high level
Example:
- The high cost of raw materials is keeping prices up.
to continue something at the same, usually high, level
Example:
- The enemy kept up the bombardment day and night.
- We're having difficulty keeping up our mortgage payments.
- Well done! Keep up the good work/Keep it up!
to make something remain at a high level
Example:
- They sang songs to keep their spirits up.
to continue to use or practise something
Example:
- to keep up old traditions
- Do you still keep up your Spanish?