brain

The word “brain” means the organ inside the skull that controls thought, memory, emotion, and the rest of the nervous system. In plain terms, the organ that lets you think, or, informally, cleverness/intelligence itself.

“Brain” is pronounced BRAYN (/ˈbɹeɪ̯n/ in IPA).

Here is “brain” used in a sentence: “A concussion is an injury to the brain.”

Words with a similar meaning to “brain” include encephalon and harns.

Depending on how it is used, “brain” can be a noun and a verb.

The word “brain” comes from Old English. From Old English brægn, going back to a Proto-Germanic root for the same organ.

“Brain” is a very common word in modern English, usually learned at around the A1 level.

“Brain” has 4 distinct senses listed in this dictionary. The most common is: the organ inside the skull that controls thought, memory, emotion, and the rest of the nervous system.

The brain is the physical organ inside the skull — tissue, cells, and electrical activity you could hold in your hand. The mind refers to the thoughts, feelings, and awareness the brain produces. Put simply, the brain is the hardware and the mind is what that hardware experiences and does.

The brain is usually divided into three broad regions. The cerebrum handles thought, the senses, and voluntary movement; the cerebellum coordinates balance and fine motor control; and the brainstem manages automatic functions like breathing and heartbeat. Together they run both conscious activity and the processes you never notice.

To a degree, yes. Through a property called neuroplasticity, the brain forms and strengthens connections in response to learning and practice. Study, new skills, exercise, and good sleep can all support memory and thinking, though there is no shortcut that permanently boosts raw intelligence.

The brain controls almost everything you do. It processes what your senses take in, stores memories, generates emotion, drives decisions, and regulates the body through the nervous system — including automatic functions such as breathing. Without it, neither conscious thought nor basic survival would be possible.