Standard Lemma guide

surprisal

noun · 6 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

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  • /sə(ɹ)ˈpɹaɪzəl/

1

noun

Meaning 1

A surprise attack or ambush; a sudden or unexpected assault.

Definition source: English Wiktionary via Wiktextract

Usage: countable, obsolete, uncountable

Topics: government, military, politics, war

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

A sudden coming-upon someone or something unexpectedly or unawares.

Definition source: English Wiktionary via Wiktextract

Usage: countable, obsolete, uncountable

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

3

noun

Meaning 3

A surprising event or occurrence.

Definition source: English Wiktionary via Wiktextract

Usage: countable, obsolete, uncountable

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

4

noun

Meaning 4

The feeling caused by being surprised; surprise, shock, amazement.

Definition source: English Wiktionary via Wiktextract

Usage: countable, obsolete, uncountable

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

5

noun

Meaning 5

An information measure as equal in bits (binary digits) to the base-2 log of 1 over the probability, with the result that the number of choices equals 2n where n is the number of bits.

Definition source: English Wiktionary via Wiktextract

Usage: countable, uncountable

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: Shannon information

Antonyms: none provided

6

noun

Meaning 6

the act of surprising someone

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: surprise

Antonyms: none provided

Broader terms: disruption, perturbation

History

Etymology

From surprise + -al. (information measure): Defined by Myron Tribus in the 1961 book Thermostatics and Thermodynamics.