the.com/blockhead
a skull so dense the thoughts just bounce off and leave.
means an insulting term for someone stupid or slow-witted, dumb as a block of wood.
from from block, meaning a solid chunk of wood used by hatmakers and carpenters, plus head — so literally a head made of wood, first recorded insulting people this way in the 1500s.
shakespeare used itappears in henry vi and cymbeline as an insult
charlie brown nicknamelucy calls him blockhead repeatedly in peanuts
related to blockheadedadjective form still common in british slang
for instance
charlie brown — lucy van pelt calls him this constantly in peanuts comics
hatter blocks — wooden head-shaped forms hatmakers used, origin of the term