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arc (ärk)
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n.
1. Something shaped like a curve or arch: the vivid arc of a rainbow.
2. Mathematics A segment of a circle.
3. An electric arc.
4. Astronomy The apparent path of a celestial body as it rises above and falls below the horizon.
5. A progression of events suggesting narrative cohesion, especially one that rises to a climax and settles to a final conclusion.
intr.v. arced (ärkt), arc·ing (ärkĭng), arcs
1. To form an arc.
2. To move or seem to move in a curved path: the stars that arc across the sky.
[Middle English ark, from Old French arc, from Latin arcus.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
 
ARC
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abbr.
1. AIDS-related complex
2. American Red Cross
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:

    Indo-European Roots

    Semitic Roots

    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.

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