Definition of fathom
(Entry 1 of 2)
1
: a unit of length equal to six feet (1.83 meters) used especially for measuring the depth of water
—sometimes used in the singular when qualified by a number five fathom deep
2
: comprehension
the themes display a newer fathom than the technical modernism of the composer's earlier works — Newsweek
fathom
verb
fathomed; fathoming; fathoms
Definition of fathom (Entry 2 of 2)
1
: to measure by a sounding line
2
: to penetrate and come to understand
couldn't fathom the problem
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Time Traveler for fathom
The first known use of fathom was before the 12th century
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