I have been using "rule of thumb" to apply a commonly used rule or practice to a specific incident, using this approximate knowledge to make a decision.
(Bad) Example: I am not hungry as of yet, but according to rule of thumb I will be requiring three meals and a bottle or two of wine by the end of today.
Awhile back, someone (somewhere) quickly explained to me the phrase's origin. The "rule of thumb" referred to an old British law which gave husbands the permission to beat his wife with a stick no longer than the width of a thumb.
Could this be true? Could my innocent little idiomatic phrase be offending feminists? I did some digging.
