The term 'LAST LETTER OF THE GREEK ALPHABET' can be answered with the word 'OMEGA' (5 letters). OMEGA is the 24th and last letter of the Greek alphabet. It is used to represent the end or conclusion of something, such as a series or sequence. In mathematics, it is often used to denote the limit of a function. In physics, it is used to represent the ohm, a unit of electrical resistance. In chemistry, it is used to represent the molecule's orientation in space. In religion, it is often used to symbolize God or eternity.