off·side (ôfsīd, ŏf-) also off·sides (-sīdz)
adv. & adj.
1. Sports Illegally ahead of the ball or puck in the attacking zone.
2. Football Illegally beyond the line of scrimmage when the ball is snapped or ahead of the ball when the ball is kicked on a kickoff.
An offside motion or play.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.