Definition of "arch" []

• A structure, especially one of masonry, forming the curved, pointed, or flat upper edge of an open space and supporting the weight above it, as in a bridge or doorway. (noun)
• A structure, such as a freestanding monument, shaped like an inverted U. (noun)
• A curve with the ends down and the middle up: the arch of a raised eyebrow. (noun)
• Anatomy An organ or structure having a curved or bowlike appearance, especially either of two arched sections of the bony structure of the foot. (noun)
• To provide with an arch: arch a passageway. (verb-transitive)

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.

• "MISCELLANEOUS WORDS. adobe _ado'ba_ algebra not _bra_ alien _alyen_, not _alien_ ameliorate _amelyorate_ antarctic _antarktik_ anti not _anti_ archangel _arkangel_ archbishop _arch_, not _ark_ arch fiend _arch_, not _ark_ architect _arkitect_ awkward _awkward_, not _ard_"
• "Especially rich were the half-dome of the apse and the wall-space surrounding its arch and called the _triumphal arch_; next in decorative importance came the broad band of wall beneath the clearstory windows."
• "The development of fan-vaulting had led to the adoption of a new form of arch, the four-centred or _Tudor arch_ (Fig. 133), to fit under the depressed apex of the vault."