Is firefighting one word or two?

Answer 1

The correct way to write this is firefighter. So your answer is one word.
It is often debated to be two words, especially in some minority areas of North America. However this is incorrect, according to official English dictionaries, where it is listed as one word.

Dictionary sources:

• Merriam Webster
• Oxford Official

Firefighters are also often referred to as firemen or firewomen, depending on their gender.
The word "fireman" existed first, coming into existence around the year 1620 to describe people who contained fires, first in military roles, before expanding to the civil service sector as well.
However in the year 1903 it was officially changed to "firefighter" to be gender neutral, as firefighters were often volunteers from both genders.
Their job is firefighting.

Answer 2

"Firefighter" is one word, also commonly known as a "fireman" although they can be male or female. He or she is a rescuer extensively trained in firefighting.

Answer 3

Two.