The term 'A While Back' can be represented by four different crossword solutions: ERST (4 letters), AGO (3 letters), ONCE (4 letters), and SOMETIMEAGO (11 letters). ERST is an archaic word meaning 'FORMERLY' or 'in the past'. AGO is a more commonly used word meaning 'before now'. ONCE is an adverb meaning 'at one time in the past'. SOMETIMEAGO is a compound word meaning 'at some point in the past'. All of these words refer to a period of time that has already passed.