having the mouth open, especially as an indication of astonishment, bewilderment, etc.

Origin of slack-jawed

slack jaw + -ed3 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for slack-jawed

Historical Examples of slack-jawed

  • Hang up, some of you, and make wax for these slack-jawed sisters.

    Actions and Reactions

    Rudyard Kipling

  • It was Lee, leaning, slack-jawed, against a pillar and reading the Green Sheet.

    The Syndic

    C.M. Kornbluth

  • "Fill your belly," he said, grinning at the youth's slack-jawed expression.

    The Return of Tharn

    Howard Carleton Browne

  • Pillbot stared from the visible portion of Gault to slack-jawed Harper and back again, sweat splashing from his puffy face.

    The 4-D Doodler

    Graph Waldeyer

  • He turned and fixed a cold, commanding eye upon the slack-jawed herders.

    Flying U Ranch

    B. M. Bower

Word Origin and History for slack-jawed

1882, "over-talkative," from slack-jaw (n.) "impertinent language" (1797), from slack (adj.) + jaw (n.). Meaning "open-mouthed and speechless" from astonishment, stupidity, etc., is from 1905.

Online Etymology Dictionary, © 2010 Douglas Harper