hump
A rounded bump that sticks up from a surface.
Hump is a rounded bump or raised part that sticks up from a surface. Camels have humps on their backs where they store fat (not water, as people often think). The fat provides energy when food is scarce in the desert. A speed bump in a parking lot is sometimes called a hump because it rises up from the flat pavement.
The word also describes getting over a difficult point in something. When you're working on a tough project and reach “the hump,” you've pushed through the hardest part and the rest should be easier. Teachers might say a class is “over the hump” once students understand a tricky concept, meaning the challenging learning is behind them.
In geography, a small rounded hill is sometimes called a hump. You might also hear someone say they “humped” heavy boxes up the stairs, meaning they hauled them with effort.
The phrase hump day refers to Wednesday, the middle of the work week. Once people get over Wednesday's hump, they're heading toward the weekend.