deep
UK[diːp]US[diːp]
adj
Extending far down from the top or surface
adj
Very intense or extreme
adj
(of sound) low in pitch; full-toned
adj
(of colour) dark and intense
adj
Difficult to understand; profound
n
A deep part of the sea or ocean
Etymology
The word 'deep' originates from the Old English 'dēop', which carried the same core meaning of extending far downward. This Old English term is derived from the Proto-Germanic 'deupaz', a concept also related to depth. The Proto-Germanic root can be traced further back to the Proto-Indo-European (PIE) root 'dheub-', meaning 'deep' or 'hollow'. This ancient root connects 'deep' to a family of words across Indo-European languages, all sharing the fundamental concept of profound vertical extension or interior space. The semantic journey from the literal, physical sense of depth to abstract meanings like profound thought or intense feeling is a classic example of metaphorical extension, where a concrete spatial concept is applied to describe intangible qualities.
Analysis
The word 'deep' is a simplex word of Germanic origin. It cannot be meaningfully segmented into smaller morphemes in modern English spelling.
Examples
They drilled a deep well in search of water.
He fell into a deep sleep after the long journey.
Her comments were too deep for the young students to understand.