bulge
n. countable B2 Upper Intermediate US //ˈbəɫdʒ// UK //bˈʌldʒ// bulge
n. a rounded part that sticks out from a flat surface. You use this to describe something that is swelling or pushing outward.
n. a rounded protuberance or swelling that results from internal pressure or overcrowding. Refers to a physical displacement outward from an otherwise level or smooth surface.
I noticed a small bulge in the tire.
The heavy wallet created a noticeable bulge in his back pocket as he sat down.
Structural engineers monitored the slight bulge in the retaining wall, concerned that the recent heavy rains had increased the soil pressure beyond safe limits.
Usage
Often used with the preposition 'in' to indicate the location of the swelling.