lump

Explanation

1. lump
A pathologically abnormal lump of skin that sticks out.

2. bump
A swelling in the muscle that is caused by contusion.

3. nodule
A swelling in plants' stems, roots, etc.

4. swelling; hump
A bulge above the surface of something.

5. burden
(figurative) A thing, person, etc., that is burdensome.