bolthead

[bohlt-hed]

noun

the head of a bolt.
Chemistry. (formerly) a matrass.

Origin of bolthead

late Middle English word dating back to 1425–75; see origin at bolt¹, head

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for bolthead

Historical Examples of bolthead

If I'd 'a' called it a bolthead it would 'a' done just as well.
The Adventures of Huckleberry Finn
Mark Twain
Let a condensed beam be sent through a large flask or bolthead containing common air.
Fragments of science, V. 1-2
John Tyndall