deep
HighAll (Common in formal and informal contexts)
Definition
Meaning
Extending far down from the top or surface.
Involving great intensity, seriousness, complexity, or penetration. Can refer to physical depth, emotional intensity, profound thought, colour saturation, sound pitch, or a position far within.
Linguistics
Semantic Notes
Primarily an adjective, but can function informally as an adverb and as a noun (e.g., 'the deep'). Its meaning spectrum spans the concrete (physical distance) to the abstract (profound thought).
Dialectal Variation
British vs American Usage
Differences
Minimal. 'Deep' as an adverb (e.g., 'dig deep') is more established in AmE, though also accepted in BrE, which sometimes prefers 'deeply'. In sports like cricket and football, 'deep' has specific positional uses.
Connotations
Largely identical. 'Deep state' is a political term more prevalent in AmE discourse.
Frequency
Equally high frequency in both varieties.
Vocabulary
Collocations
Grammar
Valency Patterns
deep in [noun] (deep in thought)[noun] is [number] metres deepdeeply [verb-ed] (deeply concerned)Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “in deep water”
- “go off the deep end”
- “deep down”
- “between a rock and a hard place (related)”
- “still waters run deep”
Usage
Context Usage
Business
"We need to do a deep dive into the quarterly figures."
Academic
"The study requires a deep understanding of quantum mechanics."
Everyday
"The shelf needs to be at least 30cm deep."
Technical
"The neural network has ten deep layers."
Examples
By Part of Speech
verb
British English
- (Rare as verb) The team will look to deep clean the facilities.
American English
- (Rare as verb) We need to deep-six this old proposal.
adverb
British English
- They had to dig deep to find the remains.
- (Often 'deeply') He was deeply moved by the speech.
American English
- Breathe deep before you start.
- The roots grow deep into the soil.
- He's in deep, financially.
adjective
British English
- The lake is remarkably deep here.
- She has a deep affection for classical music.
- He's in deep trouble with the manager.
American English
- We dug a deep hole for the pool.
- That's a deep cut from their first album.
- The company has deep pockets for acquisitions.
Examples
By CEFR Level
- The swimming pool is two metres deep.
- The box is not very deep.
- She has deep blue eyes.
- Take a deep breath and try to relax.
- He fell into a deep sleep.
- I have a deep fear of heights.
- The article offers a deep analysis of the economic crisis.
- They are deep in discussion about the merger.
- His comments were deep and philosophical.
- The government is deep in debt after the stimulus packages.
- Her new novel explores the deep-seated prejudices of society.
- The submarine ventured into the deep ocean trenches.
Learning
Memory Aids
Mnemonic
Imagine a DEEP well. DEEP has two 'e's, like two eyes looking down into a deep, dark hole.
Conceptual Metaphor
KNOWING/UNDERSTANDING IS SEEING; IMPORTANT IS DEEP (e.g., deep meaning, deep issues). EMOTIONS/STATES ARE CONTAINERS (e.g., deep in love, deep in debt).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Avoid using 'deep' for time duration (use 'long') as in 'a long meeting', not 'a deep meeting'.
- Do not confuse 'deep voice' (низкий голос) with 'low voice' (тихий голос).
- The phrase 'deep in thought' is a set phrase; translating 'deep' directly here as 'глубоко' is correct but the structure is fixed.
Common Mistakes
- Using 'deep' as a standard adverb where 'deeply' is required in formal writing (e.g., 'I deeply regret the error' vs. informal 'I'm deep in regret').
- Confusing 'deep' with 'wide' (depth vs. breadth).
- Overusing 'deep' for emotional intensity when more specific words like 'profound', 'intense', or 'heartfelt' are better.
Practice
Quiz
In which sentence is 'deep' used metaphorically?
FAQ
Frequently Asked Questions
'Deep' is primarily an adjective. As an adverb, 'deep' is often used for literal, physical depth ('dig deep') or in set phrases. 'Deeply' is the standard adverb for figurative or emotional intensity ('deeply concerned', 'deeply in love').
Not directly. We say 'a long time' or 'late at night' (e.g., 'deep into the night' is an established idiom). 'A deep meeting' is incorrect for a long meeting.
It is neutral and used across all registers. Its formality depends on context and collocation (e.g., 'profound' can be more formal than 'deep' in academic writing).
It means a thorough, detailed examination or analysis of a specific subject, problem, or dataset.