dilate: meaning, definition, pronunciation and examples
C1Formal to neutral; semi-technical in medical/scientific contexts.
Quick answer
What does “dilate” mean?
To make or become wider or larger.
Audio
Pronunciation
Definition
Meaning and Definition
To make or become wider or larger; to expand.
To speak or write at length on a subject; to elaborate.
Dialectal Variation
British vs American Usage
Differences
No significant difference in core meaning or usage. Both use the term in medical/technical contexts equally.
Connotations
Neutral in both. The figurative use ('dilate upon') may be perceived as slightly more literary or old-fashioned in both varieties.
Frequency
Similar frequency. Slightly higher in American English due to common references to 'dilated pupils' in police/medical TV dramas.
Grammar
How to Use “dilate” in a Sentence
[intransitive] The pupils dilated.[transitive] The optometrist will dilate your eyes.[intransitive + on/upon] He dilated on the complexities of the plan.Vocabulary
Collocations
Examples
Examples of “dilate” in a Sentence
verb
British English
- The midwife confirmed the cervix had begun to dilate.
- She declined to dilate further upon her personal feelings.
American English
- The optometrist will dilate your eyes for the retinal exam.
- He dilated on the topic for nearly an hour.
adverb
British English
- The blood vessels expanded dilatably in response to heat. (Rare/Technical)
- N/A
American English
- N/A
- N/A
adjective
British English
- The patient presented with dilated pupils.
- A dilated cardiomyopathy was diagnosed.
American English
- She had dilated pupils from the medication.
- The scan showed a dilated aortic root.
Usage
Meaning in Context
Business
Rare. Possibly in metaphorical sense: 'The report dilates on the market risks.'
Academic
Common in medical, biological, and physical sciences texts (e.g., 'capillaries dilate'). Also in humanities when meaning 'to elaborate'.
Everyday
Most common in health contexts: 'The drops will dilate your pupils for the exam.'
Technical
Core term in medicine, optometry, and physiology.
Watch out
Common Mistakes When Using “dilate”
- Misspelling as 'dialate'.
- Incorrect preposition: 'dilate about' (use 'on' or 'upon').
- Using transitively for non-medical contexts sounds odd: 'He dilated the story.'
FAQ
Frequently Asked Questions
It is common in medical, scientific, and formal contexts, but less common in casual everyday conversation outside specific situations like eye exams or childbirth.
'Dilate' typically refers to the widening of a circular or tubular opening (pupils, blood vessels, cervix). 'Expand' is more general, referring to increase in any dimension, volume, or scope.
Not in standard modern English. Historically, it could mean 'to delay', but this is now obsolete. The core meaning is spatial expansion.
The standard pronunciation in both British and American English starts with the 'die' sound (/daɪ/). The pronunciation 'dih-late' (/dɪˈleɪt/) is non-standard and rare.
To make or become wider or larger.
Dilate is usually formal to neutral; semi-technical in medical/scientific contexts. in register.
Dilate: in British English it is pronounced /daɪˈleɪt/, and in American English it is pronounced /ˈdaɪ.leɪt/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “dilate on/upon something”
- “eyes dilated with fear”
Learning
Memory Aids
Mnemonic
Think of a DIameter getting LATEly larger. DI-LATE = make the diameter arrive late because it's getting bigger.
Conceptual Metaphor
KNOWING IS SEEING / ATTENTION IS LIGHT ('Her eyes dilated with interest' – as if taking in more light/information).
Practice
Quiz
In which context is 'dilate' used figuratively?