Fathom (fă&thlig_;ŭm), n. [OE. fadme, faðme, AS. fæðm fathom, the embracing arms; akin to OS. faðmos the outstretched arms, D. vadem, vaam, fathom, OHG. fadom, fadum, G. faden fathom, thread, Icel. faðmr fathom, Sw. famn, Dan. favn; cf. Gr. &unr_;&unr_;&unr_;&unr_;&unr_;&unr_;&unr_;&unr_;&unr_;&unr_; to spread out, &unr_;&unr_;&unr_;&unr_;&unr_;&unr_;&unr_; outspread, flat, L. patere to lie open, extend. Cf. Patent, Petal.] 1. 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.
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2. The measure or extant of one's capacity; depth, as of intellect; profundity; reach; penetration. [R.]
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Another of his fathom they have none
To lead their business. Shak.
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