Other forms: prolonged, prolonging, prolongs
To prolong is to make something last longer. Prolong the agony, prolong life, prolonged exposure.
It is neutral about whether that is welcome: prolonging a holiday is good and prolonging the agony is the fixed phrase for the opposite. Prolonged as an adjective is standard in medical and technical writing — prolonged exposure, prolonged use. Note prolongation; and that prolong and purloin are the same Latin word, one meaning to lengthen and one to steal, which took a very strange path.
1verbprolongTo make something last longer.
“The doctors used machines to prolong his life.”
prolong is a lengthening.
Also accepted in games: extend, lengthen
Latin prolongare is pro plus longus, long. Purloin is the same word arriving through French, having gone from putting off to removing to stealing.
Proto-Indo-European
*per-
Latin
prōlongō
Old French
prolonguer
English, today
prolong
Either a a back-formation from prolongation, or from Old French prolonguer or porloignier, from Latin prōlongō, from prō + longō. a doublet of purloin.
Etymology from Wiktionary, CC BY-SA