Definition of "extra-" [ex•tra-]

• Outside; beyond: extraterritorial. (prefix)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The worst thing about this ongoing kerfuffle over superinjunctions is that it keeps forcing me to contemplate the extra- curricular activity of men who kick balls around lawns for a living."
• "Follow extra- with a hyphen when it is part of a compound modifier describing a condition beyond the usual size, extent or degree:"
• "Do not use a hyphen when extra- means outside of unless the prefix is followed by a word beginning with a or a capitalized word:"