pro·tru·sion 
/proʊˈtru:ʒən/ noun
plural pro·tru·sions /proʊˈtru:ʒən/ noun 1 [count] : a part that sticks out
▪ bony protrusions on the outside of the elbow ▪ a roof with many protrusions 2 [count, noncount] : the act of sticking out or the condition of something that sticks out
▪ The pain was caused by a/the protrusion of a disc in his lower back.
▪ bony protrusions on the outside of the elbow ▪ a roof with many protrusions
▪ The pain was caused by a/the protrusion of a disc in his lower back.
