TASK DEFINITION: Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.
PROBLEM: the scrotum is the bag that holds the testicles (commonly called "balls") in male mammals.

SOLUTION: scrotum

PROBLEM: joe the plumber, nickname of "samuel joseph "joe" wurzelbacher", (born december 3, 1973 in toledo, ohio) is an american commentator, motivational speaker and political activist.

SOLUTION: joe the plumber

PROBLEM: freemasonry is an organization of people who believe in brotherhood and helping others.

SOLUTION:
freemasonry