unfathom

English

Etymology

From un- +‎ fathom, possibly created by analogy with untangle, unravel, etc.

Verb

unfathom (third-person singular simple present unfathoms, present participle unfathoming, simple past and past participle unfathomed)

(transitive) to come to comprehend; demystify.
- 1823, M. Aikin, David Hughson, Memoirs of Religious Impostors from the Seventh to the Nineteenth Century:
  […] if the anatomists and physicians find it beyond their penetration to unfathom the mysterious depths in the texture, generation, growth, and operations, of the human body; […]
- 1845, Love and Crime; or the Mystery of the Convent, page 66:
  De Vortimer started up, and drawing his sword “By heavens,” said he, “tell me which of you have done this, or I will tear the secret from your hearts! This is some base plot, which I will unfathom ere you leave the chamber.”
- 1891, Richard Woods, A Practical Guide to Successful Pigeon Culture, page 41:
  “Scientific ” breeding is a subject worthy of much discussion, and one that has long engaged my closest attention. Happy should be the man able to unfathom its many mysteries.
- 1979, Thomas Dilworth, The Liturgical Parenthesis of David Jones, page 12:
  A body in the forward zone, buried or unburied, is
  Each night freshly degraded like traitor-corpse, where his heavies flog and violate; each day unfathoms yesterdays unkindness; dung-making Holy Ghost temples.
- 1992, Vincent Crapanzano, Hermes' Dilemma and Hamlet's Desire:
  The King smells danger and will ship Hamlet off to England; Polonius wants to try one last time to unfathom the prince.
- 2017, Clive James, Clive James On Television:
  A voiceover at our end warned that we might find it 'a bit of a mystery to unfathom what's going on'. But really it was not all that hard to unfathom. Even when you couldn't follow the American commentators you could tell they were talking sense.

Usage notes

Though attested for over 100 years, the word unfathom is absent from most dictionaries. It is considered by some to be an erroneous formation stemming from a lack of understanding that fathom itself already has the correct meaning, or a confusion with other un- words with similar meaning such as unravel, or erroneous transference of the prefix from unfathomable or unfathomed.

Synonyms