The prefix retro-, meaning “backward, back,” comes from the Latin prefix retro-, meaning “backward, behind.” The most common English words beginning with retro- are derived from Latin words or elements. Retroactive comes from Latin retro- and the verb agere, “to drive.” Retrograde combines retro- with the verb gradi, “to walk.” Retrospect adds retro- to the verb specere, “to look at.” The 19th and 20th centuries have seen many scientific or technical terms coined with English retro-, such as retrorocket.
