The term "O-shaped" can be synonymous with several different expressions. Some of the alternatives that can be used instead include "circular," "ring-shaped," "round," and "annular." Additionally, the term "oval" may also work as a synonym as it encompasses a similar overall shape to the letter O. Several other options include "cyclic," "wheel-shaped," "discoid," and "hoop-shaped." Whatever alternative is chosen, it's essential to select a term that accurately reflects the intended meaning of "O-shaped" to ensure clarity and precision in written or spoken communication.