Great question! Dwindle usually means to decrease very very slowly... For example: you might have a group of people who do something together, but over many months, bit by bit, the groups dwindles... until you see there's no one left. It's like "fade" but for something you can count in numbers. You might also say, "through the long, cold winer, our supplies dwindled until we were not sure there would be enough to last until spring" You would also say "dwindled in numbers" Shrink is most often used to refer to SIZE (rather than numbers) - a piece of clothing shrinks in the wash - the company's earnings shrank in the wake of the disaster - Trump's lead in the race for President should shrink every time he open his mouth... strangely, it does not!