surprisal

plural surprisals

1. countableobsoleteuncountablegovernmentA surprise attack or ambush; a sudden or unexpected assault.First known use 16th–19th c.

   Their chiefe attempts are by Stratagems, trecheries, or surprisals.

   1624, John Smith, Generall Historie, Kupperman, published 1988, page 146

2. countableobsoleteuncountableA sudden coming-upon someone or something unexpectedly or unawares.First known use 17th c.

   How to secure the lady from surprisal

   1646 (indicated as 1645), John Milton, “Comus”, in Poems of Mr. John Milton, […], London: […] Ruth Raworth for Humphrey Mosely, […], →OCLC

   1 more example

   Because death is uncertain, let us prevent its surprisal.

   a. 1678 (date written), Isaac Barrow, “(please specify the chapter name or sermon number)”, in The Works of Dr. Isaac Barrow. […], volume (please specify |volume=I to VII), London: A[braham] J[ohn] Valpy, […], published 1830–1831, →OCLC

3. countableobsoleteuncountableA surprising event or occurrence.First known use 17th–19th c.
4. countableobsoleteuncountableThe feeling caused by being surprised; surprise, shock, amazement.First known use 17th–19th c.
5. countableuncountableAn 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.

   1 more example

   Because language is produced and processed over time, we get it bit by bit. This allows a measure of the goodness of an incoming word according to how expected it was, given the preceding context: its expectedness or surprisal. Surprisal and expectedness are inverses: When an incoming word is highly expected, its surprisal is close to zero.

   2025, Edward A. F. Gibson, “Preliminaries: Components of Language Structure” (chapter 2), in Syntax: A Cognitive Approach, MIT Press, →DOI, →ISBN, pages 23–24

   Synonyms: Shannon information