| 释义 |
arc
I. \ˈärk, ˈȧk\ noun
(-s)
Etymology: Middle English ark, from Middle French arc, from Latin arcus bow, arc — more at arrow
1. : the apparent path described above and below the horizon by the sun or other celestial body
2. : something that is arched or curved : an arched or curved shape or figure
< with eyebrows raised in a quizzical arc >
< he bent the twig into an arc >
as
a. obsolete : arch
< triumphal arcs — John Milton >
b. : a geologic or topographic feature repeated along a curving line on the earth's surface
< island arcs … so well developed in the western Pacific — F.P.Shepard >
< volcanic arcs >
c.
(1) : a sustained brilliantly luminous glow sometimes having the appearance of a curved line of flame that is formed under certain conditions when a break is made in an electric circuit
(2) : a spotlight or lamp that uses an electric arc as the light source
d. : one of the curved stripes that close the open angle at the bottom or top of certain chevrons on military uniforms
e. : the quarter circle enclosing the service box on a squash rackets court
3. : a continuous portion of a curved line or path (as part of a circle or an ellipse)
4. : angular measure — used chiefly in the phrase of arc
< 11 minutes 3 seconds of arc >
II. intransitive verb
(arced \-kt\ ; arced \“\ ; arcing \-kiŋ\ ; arcs)
1. : to form an electric arc
2. : to follow or describe a curving course resembling the form of an arc
< waterfalls arc outward into … white plumes — C.H.Baker >
< the meandering Kum river, arcing around Taejon — Newsweek >
III. noun
: trajectory : span |