fathom

Universal Words verb, noun verb ~ sb/sth (out) to understand or find an explanation for sth: [VN] It is hard to fathom the pain felt at the death of a child. * [Vwh-] He couldn't fathom out what the man could possibly mean. noun a unit for measuring the depth of water, equal to 6 feet or 1.8 metres: The ship sank in 20 fathoms. * (figurative) She kept her feelings hidden fathoms deep.