The term 'FORMAL GREETING' can be represented by three different crossword solutions: SIR (3 letters), CURTSY (6 letters), and HOWDOYOUDO (10 letters). A formal greeting is a polite way of introducing oneself to another person. The most common formal greeting is 'SIR, ' which is used when addressing a man. A CURTSY is a gesture of respect, usually performed by a woman, in which the person bows their head and bends their knees slightly. Lastly, 'How do you do?' is a phrase that is used as a polite greeting when meeting someone for the first time.