keep up
verb()
lengthen or extend in duration or space
Examples:
Keep up the good work.
keep up
verb()
keep informed
Synonyms: follow, keep abreast,
keep up
verb()
keep in safety and protect from harm, decay, loss, or destruction
Examples:
The old lady could not keep up the building.
keep up
verb()
maintain a required pace or level
Examples:
He could not keep up and dropped out of the race.
keep up
verb()
prevent from going to bed at night