1. The act or an instance of becoming open or being made to open: the opening of the tomb.
a. A gap, breach, or aperture: slipped through an opening in the hedge.
b. A clearing in the woods.
a. The first part or stage, as of a book.
b. The first performance: the opening of a play.
c. A formal commencement of operation: attended the opening of the new museum.
d. A specific pattern or series of beginning moves in certain games, especially chess.
a. An opportunity affording a chance of success. See Synonyms at opportunity.
b. An unfilled job or position; a vacancy.
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.