late 14c., from Old French prolongation (14c.), from Late Lation prolongationem (nominative prolongatio), noun of action from past participle stem of Latin prolongare "to prolong, extend," from Latin pro "forth" (see pro-) + longus "long" (adj.); see long (adj.).
there was an indefinite prolongation of the peace talks
prolific
prolix
prolixity
prologue
prolong
prolongation
prom
promenade
Promethean
Prometheus
promethium