time constant: meaning, definition, pronunciation and examples
C1/C2 (Technical)Formal, Technical/Scientific
Quick answer
What does “time constant” mean?
In engineering and physics, a measure of the time required for a system's response to change by a specific factor (typically about 63%) in response to a step input.
Audio
Pronunciation
Definition
Meaning and Definition
In engineering and physics, a measure of the time required for a system's response to change by a specific factor (typically about 63%) in response to a step input; it characterizes the speed of an exponential response.
More broadly, it can refer to any characteristic time scale over which a process exhibits exponential decay or growth, or a parameter that defines the temporal behavior of a dynamic system.
Dialectal Variation
British vs American Usage
Differences
No significant lexical or definitional differences. Spelling remains the same.
Connotations
Identical technical connotations in both varieties.
Frequency
Equally frequent in technical domains in both regions.
Grammar
How to Use “time constant” in a Sentence
The [noun] has a time constant of [value].The time constant for [process/system] is [value].to determine/measure the time constantVocabulary
Collocations
Examples
Examples of “time constant” in a Sentence
verb
British English
- (Not used as a verb)
American English
- (Not used as a verb)
adverb
British English
- (Not used as an adverb)
American English
- (Not used as an adverb)
adjective
British English
- (Not typically used as an adjective. The adjectival form is 'time-constant' with a hyphen, as in 'a time-constant analysis'.)
American English
- (Not typically used as an adjective. The adjectival form is 'time-constant' with a hyphen, as in 'a time-constant analysis'.)
Usage
Meaning in Context
Business
Rare, except in highly technical business sectors (e.g., semiconductor manufacturing, aerospace).
Academic
Common in physics, engineering, electronics, neuroscience, and control theory papers and textbooks.
Everyday
Extremely rare; would only be used by someone explaining a technical concept in simple terms.
Technical
Core term in relevant fields. Used precisely to specify system dynamics.
Vocabulary
Synonyms of “time constant”
Strong
Neutral
Weak
Vocabulary
Antonyms of “time constant”
Watch out
Common Mistakes When Using “time constant”
- Using it as an adjective (e.g., 'time constant value' is redundant; 'time constant' is the noun). Confusing it with 'time-invariant' (which means not changing over time).
FAQ
Frequently Asked Questions
It is a compound noun written as two separate words, not hyphenated.
Virtually never. Its meaning is highly technical and specific.
It is most commonly represented by the lowercase Greek letter tau (τ).
In a simple RC (resistor-capacitor) circuit, the time constant τ = R * C (resistance multiplied by capacitance).
In engineering and physics, a measure of the time required for a system's response to change by a specific factor (typically about 63%) in response to a step input.
Time constant is usually formal, technical/scientific in register.
Time constant: in British English it is pronounced /ˈtaɪm ˌkɒn.stənt/, and in American English it is pronounced /ˈtaɪm ˌkɑːn.stənt/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “(not idiomatic in everyday language)”
Learning
Memory Aids
Mnemonic
Think of a hot cup of coffee cooling down. The 'time constant' tells you how many minutes it takes for the temperature difference to drop to about 37% of its starting value.
Conceptual Metaphor
A SYSTEM'S SPEED IS A MEASURABLE QUANTITY (like a constant in an equation).
Practice
Quiz
What does a 'long time constant' typically imply about a system?