What does thickheadedness mean?
Thickheadedness names the quality of a person who behaves stupidly, refuses to recognize an obvious fact, or stubbornly persists despite sound advice. Although dictionary definitions often pair its two related meanings—foolishness and obstinacy—ordinary use usually treats them as overlapping: a person whose thickheadedness prevents learning from correction is both unintelligent and unwilling to yield. The noun is relatively uncommon compared with broader words such as stupidity, foolishness, or stubbornness, but it is pointed when a speaker wants to emphasize mental rigidity rather than merely a poor decision. Its tone is informal and often derogatory, so it suits criticism, argument, and character description rather than neutral academic prose. In those contexts, it can suggest someone who is not merely uninformed but resistant to information. The compound also conveys the figurative idea of a thick head: a mind in which sensible points cannot penetrate. Register and context therefore matter: using the word carelessly can sound insulting, while using it deliberately can vividly characterize obstructive reasoning.
nounThe quality of being a thickhead: stupidity combined with stubborn resistance to reason or correction.
- Stupidity or lack of intelligence.
- Obstinacy or stubbornness, especially refusal to accept correction or reasonable argument.
"Their refusal to consider any evidence was dismissed as sheer thickheadedness."
"Only thickheadedness could explain why he kept making the same mistake after being corrected."
"The report attributed the delay to administrative thickheadedness rather than a lack of resources."
A regular but uncommon plural; the noun is normally used in an uncountable sense.
"The novel presents these different varieties of thickheadednesses as comic character types."
A thick head may block sound; in thickheadedness, it also blocks reason.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does thickheadedness come from?
The word is an English formation built on thickhead, meaning a stupid or obstinate person, with the suffix -ness meaning “the quality or state of.” Thickhead and the related adjective thick-headed are recorded from the early 19th century. Its elements thick and head descend respectively from Old English þicce and hæafod, both of Germanic origin.
Related word forms
How thickheadedness is actually used
Informal and usually derogatory. It is more pointed and personal than general terms such as error or mistake, and is best suited to criticism, argument, or character description rather than neutral or formal writing.