time constant
noun
Simple meaning
The time in which a physical system's response to a step-wise change in an external variable reaches about 63% of its final value.
Pronunciation
Say it like this:
tymkahnstuhntSay the bold part a little louder.
IPA pronunciation (US)
ˈtaɪmˈkɑnstənt
This word is pronounced essentially the same in American and British English, so one transcription covers both.
IPA (International Phonetic Alphabet) is a standard way of writing speech sounds.
Definition
Everyday modern meanings first, grouped by part of speech.
noun
physics
The time in which a physical system's response to a step-wise change in an external variable reaches approximately 63% of its final (asymptotic) value.
mathematics
A characteristic of an exponential function, represented by τ in the function
For radioactivity: the decay constant.
Word Aura™
How this word commonly comes across.
Aura for this meaning
This meaning: The time in which a physical system's response to a step-wise change in an external variable reaches approximately 63% of its final (asymptotic) value.
Used this way, time constant is a specialist word with a mildly favourable edge. This is a scientific use: it names something precisely within a field of study, so it appears in research and teaching more than in conversation.
- Emotional tone
- Slightly positive
- Formality
- Specialist/technical
- Intensity
- Moderate
- How common
- Specialized
- Connotation
- Positive and appreciative
- Usage feel
- Clinical and detached
Where it naturally appears
- Science
- Academic writing
- Technical/specialist writing
Usage note
In general conversation this sense usually needs explaining — outside its field, people reach for a plainer word.
Word Aura describes common impressions, not a measurement. Tone changes with sentence, speaker, relationship and situation.
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Dictionary data from Wiktionary via the Free Dictionary API. Simple meanings, combinations and word intelligence are built from verified reference data, no AI is used to load this page.