cyclo

Cyclo is a combining form derived from the Greek kyklos, meaning circle or wheel. It is used across disciplines to denote cyclic, ring-shaped, or wheel-like concepts. In chemistry, the prefix cyclo- signals cyclic structures, as in cycloalkanes such as cyclohexane and cycloalkenes such as cyclopentene. In biology and medicine, cyclo- appears in terms like cyclooxygenase (COX), an enzyme involved in prostaglandin synthesis, and in other names that describe ring-containing molecules or cyclic processes. In mathematics and physics, cyclo- appears in terms such as cycloid (the curve traced by a point on a rolling circle), cyclotron (a circular particle accelerator), and related ring-based concepts.

In Southeast Asia, the term cyclo refers to a cycle rickshaw—a three-wheeled, pedal-powered vehicle used for passenger transport. Cyclos are common in urban areas of Vietnam and neighboring countries, where drivers and locals may simply call them “cyclos” or “xích lô.” The vehicle is valued for short urban trips and has become a recognizable feature of street life in several cities.

In popular culture, Cyclo is the title of a 1995 drama film directed by Tran Anh Hung. Set in Ho Chi Minh City, the film focuses on a young man navigating poverty and the rhythms of urban life, with its title signaling themes of repetition and circularity.

Overall, cyclo functions as a versatile root across science, transportation, and culture, conveying the sense of roundness, repetition, or cycle.