fthm ftc • ft-l · · · Info · Definitions · Synonyms · Characters · · fthm · · Text Latin · · Script 4 · · Length 1 · · Syllables Definitions · · · (noun) a linear unit of measurement (equal to 6 feet) for water depth. Synonyms: fathom. · · Noun Definition 1 (noun) (mining) a unit of volume (equal to 6 cubic feet) used in measuring bodies of ore. Synonyms: fathom. · · Noun Definition 2 Synonyms · · · fathom · · Synonym 1 Characters · · f latin small letter f U+0066 h latin small letter h U+0068 m latin small letter m U+006D t latin small letter t U+0074