Pixie and Arch

pixie

Folklore) fairies that are somewhat mischievous.
- synonyms: elf, hob, gremlin, pixy, brownie, imp
Creeping evergreen shrub having narrow overlapping leaves and early white star-shaped flowers; of the pine barrens of New Jersey and the Carolinas.
- synonyms: pyxie, pixy, Pyxidanthera barbulata

(n.) A low creeping evergreen plant (Pyxidanthera barbulata), with mosslike leaves and little white blossoms, found in New Jersey and southward, where it flowers in earliest spring.
(n.) An old English name for a fairy; an elf.

Webster's Revised Unabridged Dictionary

arch

A curved shape in the vertical plane that spans an opening.
A curved bony structure supporting or enclosing organs (especially the inner sides of the feet. )
A passageway under a curved masonry construction.
- usage: "they built a triumphal arch to memorialize their victory"
- synonyms: archway
Architecture) a masonry construction (usually curved) for spanning an opening and supporting the weight above it. (

Form an arch or curve.
- usage: "her back arches"; "her hips curve nicely"
- synonyms: curve, arc

Used of behavior or attitude. ( characteristic of those who treat others with condescension)
- synonyms: condescending, patronizing, patronising
Expert in skulduggery.
- usage: "an arch criminal"
Naughtily or annoyingly playful.
- usage: "teasing and worrying with impish laughter"; "a wicked prank"
- synonyms: impish, implike, mischievous, pixilated, prankish, puckish, wicked

(n.) A flat arch is a member constructed of stones cut into wedges or other shapes so as to support each other without rising in a curve.
(v.t.) To form or bend into the shape of an arch.
(n.) A chief.
(v.i.) To form into an arch; to curve.
(n.) Any part of a curved line.
(n.) Any place covered by an arch; an archway; as, to pass into the arch of a bridge.
(a.) Cunning or sly; sportively mischievous; roguish; as, an arch look, word, lad.
(v.t.) To cover with an arch or arches.
(a.) Chief; eminent; greatest; principal.
(n.) Usually a curved member made up of separate wedge-shaped solids, with the joints between them disposed in the direction of the radii of the curve; used to support the wall or other weight above an opening. In this sense arches are segmental, round (i. e., semicircular) or pointed.
(n.) Any curvature in the form of an arch; as, the arch of the aorta.

Webster's Revised Unabridged Dictionary

Arch is a masculine given name

ARCH is Autoregressive Conditional Heteroskedasticity. It is a time series approach that models volatility as function of previous returns.