Drumlin – A hill made of glacial till deposited by a moving glacier, usually shaped like half an egg
The drumlin is usually elongated or an oval shape, with the longer axis parallel to the former direction of ice movement.
The drummer lined (drumlin) up and did a drum roll as the egg was chopped in half. As it rolled on to the floor somebody noticed the half egg was the same shape as a drumlin.
The diagram shows the glacial deposit with grass having grown over it.
Drumlins are shaped like half an egg. They tend to exist in "swarms" rather than as isolated, individual hills – a swarm can contain tens to thousands of drumlins. All of the drumlins in a swarm are lined up in the same direction.
Most drumlins have their highest elevation (blunter end) pointing in an upstream direction, with the more gently sloping and pointed end, or tail, pointing downstream. The way to remember this is:
The upstream blunt end is called the stoss end and the downstream end is called the lee.