They prolong the date by ordering coffee and dessert after dinner.
When you read the last few pages of a good book very slowly so you can enjoy reading it longer, this is an example of a time when you prolong the book.
transitive verb-·gat·ed, -·gat·ing
Origin of prolongMiddle English prolongen from Middle French prolonguer from Late Latin prolongare from Classical Latin pro-, forth + longus, long: see pro- and long
transitive verbpro·longed, pro·long·ing, pro·longs
Origin of prolongMiddle English prolongen from Old French prolonguer from Late Latin prōlongāre Latin prō- forth ; see pro- 1. Latin longus long ; see del-1 in Indo-European roots.
(third-person singular simple present prolongs, present participle prolonging, simple past and past participle prolonged)