1. draw out, extend, prolong, protract

lengthen in time; cause to be or last longer

Example Sentences:
'We prolonged our stay'
'She extended her visit by another day'
'The meeting was drawn out until midnight'

Synonyms

• draw out
• extend
• protract

2. keep up, prolong, sustain

lengthen or extend in duration or space

Example Sentences:
'We sustained the diplomatic negotiations as long as possible'
'prolong the treatment of the patient'
'keep up the good work'

Synonyms

• keep up
• sustain