unfathomable

[uhn-fath-uh-muh-buhl]

adjective

1. not able to be fathomed, or completely understood; incomprehensible.

   heroism in the face of unfathomable conflict.

2. not able to be measured with a sounding line, or fathomed.

   unfathomable depths of the ocean.

unfathomable

/ ʌnˈfæðəməbəl /

adjective

1. incapable of being fathomed; immeasurable

2. incomprehensible

Other Word Forms

• unfathomableness noun
• unfathomably adverb

Word History and Origins

Origin of unfathomable¹

First recorded in 1610–20; un- ¹ ( def. ) + fathom ( def. ) + -able ( def. )

Example Sentences

In mitigation, defence barrister Philip Wright told the court his actions may seem "unfathomable" given the "laudable and noble" features of his political life.

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Only once did a whale come close enough for Penelope to gaze into its unfathomable eye.

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If you, like me, have a spoiled, lazy dog that enjoys cheese flavoured treats, the fact that your pet's ancestors were wild predators can seem unfathomable.

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Almost unfathomably, with the first Test not beginning until 30 November, England gathered in London more than two months earlier, at the end of September.

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To many investors, that scenario is “unfathomable,” Al writes.

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Related Words

• baffling 
• impenetrable 
• incomprehensible 
• indecipherable 
• inexplicable 
• unknowable