The term 'heavy hitter' is used to describe someone who is powerful and influential. This can be seen in the crossword solutions for the term, which include MALLET (6 letters), SLEDGE (6 letters), MOGUL (5 letters), NABOB (5 letters), MAUL (4 letters), biggun (6 letters), and smiter (6 letters). A MALLET is a tool used to hit something with force, while a SLEDGE is a large hammer. A MOGUL is a powerful businessperson, while a NABOB is a wealthy person. A MAUL is a heavy hammer, and a biggun is a powerful person. Finally, a smiter is someone who strikes with force. All of these words are related to the idea of power and influence, making them appropriate solutions for the term 'heavy hitter'.