Shoulder is the joint where your arm connects to your body, but the word carries meanings that reach far beyond anatomy.

Your shoulders are remarkably flexible joints that let you throw a ball, give a hug, or reach high shelves. They're also where you might carry a backpack, rest a tired friend's head, or feel tension knot up when you're worried.

The word appears in dozens of expressions that reveal something about how we think about responsibility and support. When you shoulder a burden, you take on a difficult task. When someone gives you the cold shoulder, they're deliberately ignoring you. To shoulder your way through a crowd means pushing through using your shoulders. A shoulder to cry on is a friend who listens when you're upset.

Roads have shoulders too: the paved or dirt area along the edge where cars can pull over in emergencies. Mountains have shoulders, which are the broad, sloping areas below the peak. Even bottles have shoulders, the curved part where the neck widens into the body.

When you work shoulder to shoulder with someone, you're working closely together as equals. The phrase captures something essential: shoulders are strong, and when people stand side by side, combining their strength, they can accomplish remarkable things.