"prolong" in the verb sense
1. prolong, protract, extend, draw out
lengthen in time cause to be or last longer
"We prolonged our stay"
"She extended her visit by another day"
"The meeting was drawn out until midnight"
2. prolong, sustain, keep up
lengthen or extend in duration or space
"We sustained the diplomatic negotiations as long as possible"
"prolong the treatment of the patient"
"keep up the good work"
Source: WordNet® (An amazing lexical database of English)
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