arch

noun10

1. •
   An arch-shaped arrangement of trapezoidal stones, designed to redistribute downward force outward.
2. •
   An architectural element having the shape of an arch
3. •
   The curved part of the bottom of a foot.
4. •
   An inverted U shape.
5. •
   Any place covered by an arch; an archway.
6. •
   A natural arch-shaped opening in a rock mass.
7. •
   An architecture; a computer architecture or instruction set architecture.

   • In the Linux kernel, arch-specific code lives in the arch directory of the source tree.
8. •
   Synonym of god (“person who owns and runs a multi-user dungeon”).
9. •
   (no longer used) An arc; a part of a curve.
10. •
    (no longer used) A chief.

    • My worthy arch and patron comes to-night. — 1593

adjective3

1. •
   Principal; primary.

   • They were arch enemies.
2. •
   Knowing, clever, mischievous.

   • I attempted to hide my emotions, but an arch remark escaped my lips.
3. •
   (Ireland) Cute, sly, prematurely wise.

verb2

1. •
   To form into an arch shape.

   • The cat arched its back.
2. •
   To cover with an arch or arches.

adjective2

1. •
   Abbreviation of archaic.
2. •
   Abbreviation of architectural.

noun5

1. •
   Abbreviation of architecture.
2. •
   Abbreviation of archaism.
3. •
   Abbreviation of architect.
4. •
   Abbreviation of archipelago.
5. •
   Abbreviation of archery.

adjective1

1. •
   Initialism of autoregressive conditional heteroskedasticity