arc
/ɑːk/ (bre, ipa) · [ˈɑrk] /ɑːrk/ (ame, ipa) · [ˈɑrk] /ˈärk/ (ame, mw)
arc — noun
- arcsingular
- arcsplural
1. A smooth, bending line — like the shape a rainbow makes in the sky, or the path
A smooth, bending line — like the shape a rainbow makes in the sky, or the path a ball follows when you throw it high.
The rainbow painted a perfect arc across the sky after the storm.
collocation: perfect arc
Adisa drew a neat arc on the whiteboard to show the bending path.
Eli watched the golf ball follow a wide arc before it dropped.
The bridge rose in a graceful arc above the dark river below.
Nadia cut the paper along a smooth arc to finish the craft project.
常見錯誤
2. A bright, continuous stream of electricity that jumps through the air between tw
A bright, continuous stream of electricity that jumps through the air between two points that are not touching.
A bright blue arc jumped between the two wires when Yan flipped the switch.
The welder's torch produced a fierce arc as it joined the metal plates.
Rodrigo saw an electric arc flash across the gap in the damaged cable.
The loud crack of an arc echoed through the power station during the test.
Workers must wear dark goggles to protect their eyes from the welding arc.
用法筆記
Common in technical contexts such as welding and electrical engineering. Not used for the small, brief sparks of static electricity — those are simply called 'sparks.'
3. The full journey of a character or the complete development of a theme across a
The full journey of a character or the complete development of a theme across a story, film, or TV series — showing how someone or something changes from beginning to end.
The villain's redemption arc made him the most memorable part of the film.
collocation: redemption arc
Romi felt moved by the main character's emotional arc across the three novels.
collocation: emotional arc
Each season of the show follows the personal arc of a different family member.
Matthew wrote a powerful arc for the young hero who learns to trust others.
The documentary traces the arc of the singer's career from garage band to stadiums.
- storyline
broader — the entire sequence of events in a plot, not just one character's progression
- trajectory
more formal; often used for careers or historical developments rather than fictional characters
- journey
more general; can describe any progression, real or fictional
用法筆記
Used mainly when discussing films, books, and TV series. Not generally used for describing real-life events or people's actual lives — it is a storytelling term.
常見錯誤
arc — verb
- arcpresent simple I / you / we / they
- arcs3rd person singular
- arcing-ing form
- arcedpast simple
1. To travel through the air or along a path following a smooth, bending line.
To travel through the air or along a path following a smooth, bending line.
The basketball arced high above the court before dropping cleanly through the net.
intransitive: arced + high above
Emre saw the arrow arc over the field and hit the centre of the target.
A flock of birds arced across the evening sky in a single smooth sweep.
Diya threw the stone and it arced out over the lake before splashing down.
The fountain's water arced gracefully into the pool, sparkling in the sun.
文法句型
arc + adverb or preposition phrase
用法筆記
Often used with a direction phrase (overhead, across, toward, into). The past tense and past participle are 'arced.' Do not confuse with the noun — the verb describes the motion itself, not the shape.
2. To produce a bright electric spark that jumps across a gap between two conductor
To produce a bright electric spark that jumps across a gap between two conductors.
The damaged cable arced loudly, sending bright white sparks across the floor.
When Nikos touched the two loose wires together, they arced with a sharp crack.
The old circuit breaker arced and filled the room with a burning smell.
Switch off the power before fixing the light, or the wires might arc.
Jin noticed the loose connection was arcing whenever the machine started up.
- spark
verb — describes a brief, smaller discharge; 'arc' implies a sustained, visible stream of electricity
文法句型
arc + adverb or preposition phrase
用法筆記
A technical term used in electrical engineering. In everyday speech, people are more likely to say 'sparked' or 'short-circuited.' The past tense is 'arced.'
arc — adjective
- arcpositive
- arcercomparative
- arcestsuperlative
1. Used in mathematics to describe inverse functions — for example, arc sine, arc c
Used in mathematics to describe inverse functions — for example, arc sine, arc cosine, and arc tangent, which reverse the usual sine, cosine, and tangent operations to find the angle.
Madison used the arc sine function to find the missing angle in the triangle.
Ms. Okonkwo opened the textbook and explained arc sine as the function that reverses sine.
Dmitri used arc cosine at the workbench to find the angle of the leaning steel strut.
The arc sine button on the calculator is often marked as sin⁻¹.
Yan pressed the arc tangent key and wrote down the result in her notebook.
- inverse
broader mathematical term — 'arc sine' and 'inverse sine' mean the same thing, but 'arc' is the traditional notation in function names
用法筆記
This is a highly technical term used only in advanced mathematics. It always appears directly before 'sine,' 'cosine,' or 'tangent' — never as a standalone adjective.