coherence

American  

[koh-heer-uhns, -her-] / koʊˈhɪər əns, -ˈhɛr- /

Also coherency

noun

1. the act or state of cohering; cohesion.

2. logical interconnection; overall sense or understandability.

3. congruity; consistency.

   Synonyms:

   rationality, agreement, harmony, correspondence

4. Physics, Optics. (of waves) the state of being coherent.

5. Linguistics. the property of unity in a written text or a segment of spoken discourse that stems from the links among its underlying ideas and from the logical organization and development of its thematic content.

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coherence British  

/ kəʊˈhɪərənsɪ, kəʊˈhɪərəns /

noun

1. logical or natural connection or consistency

2. another word for cohesion

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coherence Scientific  

/ kō-hîr′əns,-hĕr′- /

1. A property holding for two or more waves or fields when each individual wave or field is in phase with every other one. Lasers, for example, emit almost perfectly coherent light; all the photons emitted by a laser have the same frequency and are in phase. Since quantum states can be described by a wave equation, coherence can hold for quantum states in general, though only among bosons. Coherence is generally possible in physical systems that may undergo superposition. Maintaining coherence of light is important in fiber optic communications.

2. See also Bose-Einstein condensate

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Other Word Forms

• noncoherence noun
• noncoherency noun

Etymology

Origin of coherence

First recorded in 1570–80; coher(ent) + -ence

Example Sentences

This would mean "joint supervision, harmonised insolvency and greater tax coherence, which go far beyond what is currently proposed", she told AFP.

From Barron's • Mar. 16, 2026

As if the ugliness of the 120 minutes wasn't enough - the grisly battle, the hair-on-fire panic, the abysmal lack of anything resembling coherence or even competence - there was the disgrace of the post-match.

From BBC • Mar. 8, 2026

Bowe restores coherence by allowing federal prisoners to return to court when later developments reveal that earlier denials rested on conclusions the Supreme Court has since rejected.

From Slate • Jan. 10, 2026

"In this state, quantum coherence and many-body entanglement prevent the system from thermalizing and from showing diffusive behavior, even under sustained external driving," explains Hanns Christoph Nägerl.

From Science Daily • Jan. 8, 2026

Jack grabbed his shoulder and shook him, trying to either comfort the prince or shake some coherence back into him.

From "Half Upon a Time" by James Riley

Related Words

• consistency
• continuity
• integrity
• rationality
• solidarity
• unity