- fathom, fthm - a linear unit of measurement (equal to 6 feet) for water depth
--1 is a kind of linear unit
--1 has parts: yard, pace - fathom, fthm - (mining) a unit of volume (equal to 6 cubic feet) used in measuring bodies of ore
--2 is a kind of volume unit, capacity unit, capacity measure, cubage unit, cubic measure, cubic content unit, displacement unit, cubature unit