What does thickheaded mean?
Thickheaded is an informal adjective meaning stupid, slow-witted, or unusually unable to understand something. It is especially used for a person, decision, or mistake that displays poor judgment or a lack of understanding. For example, ignoring an obvious warning could be described as a thickheaded choice, while someone who repeatedly misunderstands simple instructions may be called thickheaded. The expression generally carries a negative and derogatory connotation, although its force can vary from lightly teasing to openly insulting depending on tone and context. It is especially common in British and American informal English and is also written as “thick-headed.” Although the word literally suggests having a heavy head, its established figurative meaning concerns intellectual dullness rather than a physical condition or a person's appearance. It is useful as a direct, emotionally emphatic way to characterize conspicuous foolishness or misunderstanding.
adjectiveStupid or slow-witted; lacking the intelligence or ability to understand something easily.
- Unable to think or understand easily; stupid or slow-witted.
"It was a thickheaded decision to ignore the warning signs."
"It was a thickheaded mistake to leave the door unlocked."
"He was regarded as thickheaded, although he had simply never been taught the system."
A literal heavy head becomes a quick label for a mind that seems just as difficult to get through.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does thickheaded come from?
Thickheaded is an English compound formed from thick and headed, a development that became established in early modern English. Its components have Old English origins: thick continues Old English þicce, while head continues Old English hēafod, and headed combines head with the suffix -ed. Related English forms include thicken and thickness from the first root, and heading and header from the second. The compound originally applied a physical description to intellectual dullness before becoming an established word for someone regarded as stupid or slow-witted.
Related word forms
How thickheaded is actually used
This is an informal and potentially insulting term. It is used more often in speech and informal writing than in formal or technical contexts.
Easily confused with thickheaded
Thickheaded means stupid or slow-witted, whereas thick-skinned means insensitive to criticism or the feelings of others.