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: monosemy is when the words in a language each have only one meaning.

SOLUTION: monosemy

PROBLEM: the vektor r4 is a south african assault rifle.

SOLUTION: vektor r4

PROBLEM: the pac-12 conference is a group of universities who play each other in football, basketball, and other sports.

SOLUTION:
pac-12 conference