WordReference Random House Learner's Dictionary of American English © 2019
ˈrule of ˈthumb, n. [countable]
  • a general rule based on experience, and not taken from scientific reasoning:As a rule of thumb I add a spoonful of salt.

  • WordReference Random House Unabridged Dictionary of American English © 2019
    rule of thumb, 
    1. a general or approximate principle, procedure, or rule based on experience or practice, as opposed to a specific, scientific calculation or estimate.
    2. a rough, practical method of procedure.
    • 1685–95

    Collins Concise English Dictionary © HarperCollins Publishers::

    rule of thumb n
    1. a rough and practical approach, based on experience, rather than a scientific or precise one based on theory
    2. (as modifier): a rule-of-thumb decision

    'rule of thumb' also found in these entries:

    Word of the day: dish | banter


    Report an inappropriate ad.