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 nemean lion ( ""; latin: "leo nemaeus") was a vicious monster in greek mythology that lived at nemea.

SOLUTION: nemean lion

PROBLEM: aerospace engineering is a field of engineering that specializes in vehicles that move in fluids.

SOLUTION: aerospace engineering

PROBLEM: the 2012 delhi gang rape case involved a gang rape and murder that happened on 16 december 2012 in delhi, india.

SOLUTION:
2012 delhi gang rape