The term 'Blast Maker' refers to a person who is responsible for the construction and detonation of explosives. The two crossword solutions, HORN (4 letters) and TNT (3 letters), are both materials used in the making of explosives. HORN is a type of powder made from ground up animal horns, while TNT is an explosive material made from a combination of toluene and nitric acid. Both materials are commonly used in the construction of explosives and are essential components of a Blast Maker's job.