A tough customer is someone who is difficult to please or persuade. The crossword solutions for this term are 'HOMBRE' (6 letters), 'Ironman' (7 letters), 'Hardcase' (8 letters), and 'Hardsell' (8 letters). HOMBRE is a Spanish word meaning man, and Ironman is a popular superhero character known for his strength and determination. Hardcase and Hardsell both refer to someone who is difficult to deal with, either because they are stubborn or because they are trying to get the best deal possible.