To prolong is a verb which means to make longer or to extend the length or duration of something. This word is usually associated with time or space.

1. I applied to extend my visa so that I could prolong my stay in the country without breaking the law.
2. The ongoing war in the region has prolonged the suffering of the people living there.

1. By failing to address the issue, we are merely prolonging it. We need to tackle it now!
2. I'm very happy at the company, so I agreed to prolong my contract a further year.