What does entrainment mean?
Entrainment is the process by which one thing is drawn along or carried by another, or brought into step with it. The word appears across several technical fields with closely related meanings. In fluid dynamics and engineering, entrainment describes the transport of droplets, particles, or bubbles by a moving gas or liquid — as when fast-moving steam carries water droplets out of a boiler. In chronobiology and psychology, it refers to the synchronization of an organism's internal rhythms with external cues, most familiarly the daily entrainment of the human circadian clock by morning light. Musicians and neuroscientists also use it for the way people's movements or attention lock onto an external beat. Derived from French entraîner, 'to drag along,' the term carries no emotional connotation but signals precision: it belongs to scientific and technical writing rather than everyday speech, where paraphrases like 'carrying along' or 'syncing up' would be more natural.
nounThe process by which one thing is drawn or carried along with another, such as liquid droplets carried in a gas stream or particles transported by a fluid. In biology and psychology, the synchronization of an organism's internal rhythms to an external periodic cue, such as light.
- The synchronization of a biological rhythm to an external periodic signal, especially the alignment of circadian rhythms with light–dark cycles.
- In fluid dynamics and engineering, the carrying of droplets, particles, or bubbles along by a moving fluid or gas stream.
- In chemistry, the unwanted carry-over of liquid droplets into a vapor stream, as in distillation.
- In music and psychology, the rhythmic coupling of a person's movements or attention to an external rhythm.
"High-velocity steam caused significant entrainment of water droplets from the boiler."
"Morning light exposure is essential for the entrainment of the human circadian clock."
"The scrubber was designed to minimize entrainment of liquid droplets into the exhaust stream."
Rarely pluralized; usually treated as an uncountable mass noun referring to a process.
"Different light wavelengths produce distinct entrainments of the circadian system."
Your body clock is literally dragged into line with sunrise each day — that process is called entrainment.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of entrainment
Entrainment derives from French entraîner, meaning 'to drag or draw along', formed from en- plus traîner, which traces back through Vulgar Latin *traginare to the Latin verb trahere, 'to pull or draw'. English borrowed both the verb entrain and the noun entrainment from French, with the noun becoming established in scientific usage in the nineteenth and twentieth centuries as engineers and later biologists needed a precise term for drawing-along processes. It shares its ultimate root with words such as train, trail, trait, and tractable.
Related word forms
How entrainment is actually used
A technical term used chiefly in physics, engineering, chronobiology, and psychology; rare in casual conversation. In each field it has a specialized meaning, so context determines the sense intended.
Easily confused with entrainment
Entertainment refers to amusement or diversion, while entrainment is a technical term for the drawing along or synchronization of one thing by another.