A casual farewell is a way of saying goodbye in an informal manner. The most common crossword solutions for this term are BYE (3 letters), TATA (4 letters), LATER (5 letters), and CLATER (6 letters). BYE is a short, informal way of saying goodbye, while TATA is a more playful version of the same sentiment. LATER is a phrase used to indicate that one will SEE the other person at a LATER time, and CLATER is a combination of the words 'SEE' and 'LATER'.