The term 'SIT BACK' can be broken down into four crossword solutions: UNWIND (6 letters), RELAX (5 letters), TIS (3 letters), IDLE (4 letters), and REST (4 letters). UNWIND means to become less tense or agitated, while RELAX means to make or become less tense or anxious. TIS is an abbreviation for 'that is', and IDLE means to be inactive or do nothing. Finally, REST means to take a break from activity or work. All of these words are related to the phrase 'sit back', which generally means to take a break and RELAX.