The term 'difficult work' can be described by two crossword solutions: 'TOIL' (4 letters) and 'TRAVAIL' (7 letters). TOIL is a word that means hard, often physical labor, while TRAVAIL is a word that means hard work or effort, especially when it is unpleasant or exhausting. Both words are used to describe difficult work, but TOIL is more often used to describe physical labor, while TRAVAIL is more often used to describe mental labor.