The term 'amusing bitterly' can be broken down into five crossword solutions: WRIEST (6 letters), WRYEST (6 letters), WRY (3 letters), RAIL (4 letters), and RUE (3 letters). WRIEST is an adjective meaning 'most humorous, ' while WRYEST is an adjective meaning 'most wryly humorous.' WRY is an adjective meaning 'dryly or ironically humorous, ' RAIL is a verb meaning 'to scold or criticize harshly, ' and RUE is a verb meaning 'to regret deeply.' Together, these words describe a situation that is both amusing and bitter.