Fathom

1. n. The measure or extant of one’s capacity; depth, as of intellect; profundity; reach; penetration.
2. n. A measure of length, containing six feet; the space to which a man can extend his arms; — used chiefly in measuring cables, cordage, and the depth of navigable water by soundings.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.