The term 'by CHANCE' can be defined as happening without intention or expectation. This is reflected in the crossword solutions, which include words such as 'ACCIDENTALLY' (12 letters), 'CASUAL' (6 letters), 'UNINTENTIONALLY' (15 letters), 'CHANCE' (6 letters), 'UNEXPECTEDLY' (12 letters), 'HAPLY' (5 letters), 'RANDOM' (6 letters), 'PERHAPS' (7 letters), 'CASUALLY' (8 letters), 'POSSIBLY' (8 letters), 'ARBITRARY' (9 letters), 'PERCHANCE' (9 letters), 'FORTUITOUSLY' (12 letters), and 'peradventure' (12 letters). All of these words indicate that something has happened without any prior planning or expectation.