The term 'prefix meaning 'STRAIGHT'' can be represented by four different words: ORTHO (5 letters), RECT (4 letters), RECTI (5 letters), and ORTH (4 letters). ORTHO is derived from the Greek word 'orthos, ' which means 'STRAIGHT, correct, or true.' RECT is derived from the Latin word 'rectus, ' which also means 'STRAIGHT.' RECTI is a combination of the two words, and ORTH is a shortened version of ORTHO. All four words have the same meaning: 'STRAIGHT.'