1560s, "spread the legs wide," probably an alteration of striddle (mid-15c.), frequentative of striden (see stride (v.)). Transitive sense "place one leg on one side of and the other on the other side of" is from 1670s. U.S. colloquial figurative sense of "take up an equivocal position, appear to favor both sides" is attested from 1838. Related: Straddled; straddling. The noun is first recorded 1610s.
updated on December 05, 2013