Extra- is a prefix meaning “outside,” “beyond,” and is freely used as an English formative. Examples of words with the prefix extra- include extrajudicial, extraterritorial, and extra-atmospheric. Other examples of words with the prefix extra- include: ^{dictionary.com 1 2}

• Extra credit: “outside” credit ^{membean.com 2}
• Extracurricular: “outside” the general curriculum of a school ^{membean.com 2}
• Extrasensory: of being “outside” the five senses ^{membean.com 2}
• Extraterrestrial: of being “outside” the planet Earth ^{membean.com 2}