[v] prevent from going to bed at night; "The anticipation of the trip kept the children up all night"; "I kept myself up all night studying for the exam"
[v] keep informed; "He kept up on his country's foreign policies"
[v] maintain a required pace or level; "He could not keep up and dropped out of the race"
[v] keep in safety and protect from harm, decay, loss, or destruction; "We preserve these archeological findings"; "The old lady could not keep up the building"; "children must be taught to conserve our national heritage"; "The museum curator conserved the ancient manuscripts"
[v] lengthen or extend in duration or space; "We sustained the diplomatic negociations as long as possible"; "prolong the treatment of the patient"; "keep up the good work"