fathom

Where does the word "fathom" come from? It comes from Old English fæþm, and was adopted directly into English (1600s).

Fathom’s story begins in Old English: fæþm meant “embrace; arm-span.” 'outstretched arms, embrace', and the length of the arms spread out. It reached English by 1600s as fathom. Fixed as six feet for measuring water depth, and so 'to get to the bottom of' something; Mark Twain's pen name comes from the Mississippi call 'mark twain', two fathoms. Today, fathom means a unit of depth of six feet; to understand after much thought.

1. Stage 1 · Old English · medieval fæþm "embrace; arm-span", 'outstretched arms, embrace', and the length of the arms spread out.
2. Stage 2 · English · 1600s fathom "six feet; to understand", fixed as six feet for measuring water depth, and so 'to get to the bottom of' something; Mark Twain's pen name comes from the Mississippi call 'mark twain', two fathoms.