brain
UK[breɪn]US[breɪn]
n
The organ inside the head of a person or animal that controls thought, memory, and physical activity.
n
The ability to think clearly and intelligently; the mind or intellect.
n
(informal) A very intelligent person.
Etymology
The word 'brain' originates from the Old English 'brægen', which referred directly to the organ. Its earlier Germanic root is traced to Proto-Germanic bragną, though its ultimate origin is uncertain, with possible non-Indo-European roots. The semantic journey is straightforward, maintaining its core reference to the physical organ from its earliest known usage. Over time, its meaning expanded metaphorically to encompass the seat of intelligence, thought, and mental capacity, reflecting the organ's perceived function.
Analysis
The word 'brain' is a simplex word of Old English origin. It cannot be meaningfully segmented into productive morphemes in modern English.
Examples
The human brain is an incredibly complex organ.
She has a brilliant brain for solving intricate puzzles.
He's the brains behind the company's most successful marketing campaign.