bonehead

UK: /ˈbəʊnˌhɛd/ US: /ˈboʊnˌhɛd/ ,(bōn′hed′)

WordReference Random House Learner's Dictionary of American English © 2025

bone•head /ˈboʊnˌhɛd/   Slang.
n. [countable]

1. Slang Terms a stupid person;
   blockhead:
   That bonehead even misspelled his name.

adj. 

2. Slang Terms Also, ˈboneˌhead•ed. characteristic of or done by such a person:
   a real bonehead comment.

bone•head•ed•ness, n. [uncountable]

WordReference Random House Unabridged Dictionary of American English © 2025

bone•head  (bōn′hed′), [Slang.]
n. 

1. Slang Terms a foolish or stupid person;
   blockhead.

adj. 

2. Slang Terms being of, by, or for a stupid or unthinking person:
   a bonehead mistake.

• bone¹ + head 1905–10, American.

bone′head′ed, adj. 
bone′head′ed•ness, n. 

Collins Concise English Dictionary © HarperCollins Publishers::

bonehead / ˈbəʊnˌhɛd/ noun

1. a stupid or obstinate person

ˌboneˈheaded adjective