prolonger


pro·long

P0591300 (prə-lông′, -lŏng′)tr.v. pro·longed, pro·long·ing, pro·longs To lengthen in duration; protract: factors that prolong the drug's effect.
[Middle English prolongen, from Old French prolonguer, from Late Latin prōlongāre : Latin prō-, forth; see pro-1 + Latin longus, long; see del- in Indo-European roots.]
pro·long′er n.