This is a process in which foods are soaked in liquid (like dried fruit in rum for Christmas cake) to soften them, but also for the food to absorb the flavours from the liquid. This term also refers to the treatment of fresh fruit (especially berries), when they get sprinkled with sugar and release their own juices intensifying their flavour.
Cognac soaked prunes are delicious when added to a plain custard tart or surprisingly, strong espresso,giving it a deep boozy hit.