The term 'BE OFF' can be broken down into four separate words: AIL (3 letters), ERR (3 letters), SCAT (4 letters), and GETMOVING (9 letters). AIL is a verb meaning to suffer from an illness or pain. ERR is a verb meaning to make a mistake or do something wrong. SCAT is a verb meaning to leave quickly or run away. Finally, getmoving is a verb meaning to start doing something or to take action. Together, these words form the phrase 'be off, ' which is an idiom meaning to leave or depart.