1
general::
prolong
to make something last longer:
• The issue divided the country and prolonged the civil war. • Successful treatment is prolonging people's lives. • No one wants to prolong the violence. • This would only prolong the unhappiness she felt.
lengthen
to make something last longer than the usual time:
• They suggested lengthening the training period for new teachers. • New security measures have lengthened the time passengers spend in airports.
extend
to make something that is coming to an end continue for a longer period of time – used especially about official arrangements such as contracts and visas:
• They agreed to extend his contract by a year. • The offer has been extended for a further fourteen days. • I applied to extend my visa.
drag something out
to make a situation or event last longer than necessary:
• I wish they'd make a decision and not keep dragging it out. • Each side accused the other of dragging out the negotiations.
Longman-Thesaurus
2
general::
verb ADV. indefinitely Might it be possible to prolong life indefinitely? | artificially | deliberately Doctors commented that some patients deliberately prolong their treatment. | unduly, unnecessarily We do not want to prolong the meeting unnecessarily.
Oxford Collocations Dictionary