skull

skull — noun

1. the hard bony case at the top of the body that holds and shields the brain

1.nounB1
Definition

the hard bony case at the top of the body that holds and shields the brain

Example

The archaeologist held up an ancient skull that had been buried for more than two thousand years.

collocation: ancient skull

After falling off the ladder, Zola went to the hospital to check if her skull was fractured.

collocation: fractured skull

Common collocations
  • fractured skull
  • skull fracture
  • thick skull
  • human skull
  • ancient skull
  • skull bones
Synonyms
  • cranium

    the medical or technical term for the skull, specifically the part that encloses the brain

  • head

    much broader — includes all parts of the head, not just the bone

Usage Note

Skull refers specifically to the bone, not the whole head. For soft-tissue injuries, use 'head' or 'scalp' instead.

Common Mistakes

The doctor said I bruised my skull.
The doctor said I bruised my head.
the skull is the bone inside; you bruise skin or muscle, not bone.

2. the head or brain considered as the place where thinking, understanding, or memo

2.nounB2
Definition

the head or brain considered as the place where thinking, understanding, or memory happens — often used in expressive or fixed phrases

Example

Can't you get it into your thick skull that smoking is really bad for your health?

idiom: get it into your thick skull

Theo's skull was pounding after three hours of standing near the loudspeakers at the rock concert.

Common collocations
  • thick skull
  • get it into your skull
  • empty skull
  • pounding skull
Synonyms
  • mind

    more common than the figurative 'skull' for referring to thinking and understanding

  • brain

    also used figuratively for intelligence or thought, but more direct than 'skull'

  • head

    general term; 'skull' adds a stronger, more expressive tone

Usage Note

This figurative sense appears mostly in fixed expressions such as 'out of one's skull' (crazy or very drunk), 'a thick skull' (slowness to understand), and 'get it into one's skull' (finally accept or understand something).

Common Mistakes

I have a headache in my skull.
I have a headache.
we do not usually say 'skull' to mean the whole head in everyday conversation; use 'head' instead.
Idioms

out of one's skull

idiom

extremely angry, crazy, or very drunk — used informally to describe a strong emotional or mental state

When Vivek heard about the theft, he went completely out of his skull with rage.

After five glasses of wine at the party, Dylan was completely out of his skull.

skull and crossbones

idiom

a picture of a human skull above two crossed bones, used as a symbol for poison, danger, or pirates

The cleaning bottle had a skull and crossbones on the label, so I knew it was poisonous.

The old pirate flag was black with a white skull and crossbones stitched onto it.

a thick skull

idiom

used to describe someone who is slow to understand or who refuses to accept new ideas

Eli has a thick skull when it comes to learning new languages, but he never gives up.

I tried to explain the rules three times, but Joshua has such a thick skull that nothing gets through.

skull — verb

Word family

  • skulled
    adjectiveC1
  • thick-skulled
    adjectiveC2

Synonym discussion

Sense: noun/1

All three words refer to the head area, but they differ in technical level and scope. 'Skull' is a common, everyday word for the bone structure of the head, used in both general and medical contexts. 'Cranium' is the formal anatomical term, usually reserved for medical or academic writing — a doctor might say 'the patient has a fractured cranium' in a report but 'skull fracture' when speaking to the patient's family. 'Head' is the broadest of the three, covering everything from the skull and skin and hair to the face and brain. You hit your 'head' (the whole body part), not your 'skull' (the bone inside). In everyday conversation, 'skull' is most often used in medical contexts (X-rays, injuries) or when referring to death/danger symbols, while 'cranium' would sound overly technical outside a clinical setting. For example: a boxer is said to have a 'thick skull' (figurative, meaning stubborn), but you would not say 'thick cranium' — that would sound unnatural.

skull ↗craniumhead

Common collocations

Nouns

Phrases

Etymology

Proto-GermanicOld EnglishEnglish

The word 'skull' comes from Old English 'scealu' meaning a shell or husk, which itself traces back to a Proto-Germanic root *skaljo meaning 'a bowl or shell'. The shift from 'shell' to 'head bone' happened because the skull was seen as a hard outer casing that resembles a bowl. The verb senses appeared much later: the 'hit on the head' meaning dates from the early 1900s, while the golf jargon sense emerged among British and American golfers in the mid-20th century. The word is related to 'scale' (as in fish scale) and 'shell', which share the same ancient root idea of a hard outer covering.