bluestocking (n.) Look up bluestocking at Dictionary.com
also blue-stocking, 1790, derisive word for a woman considered too learned, traces to a London literary salon founded c. 1750 by Elizabeth Montagu on the Parisian model, featuring intellectual discussion instead of card games, and in place of ostentatious evening attire, simple dress, including Benjamin Stillingfleet's blue-gray tradesman's hose which he wore in place of gentleman's black silk, hence the term, first applied in derision to the whole set by Admiral Boscawen. None of the ladies wore blue stockings. Borrowed by the neighbors in loan-translations, such as French bas-bleu, Dutch blauwkous, German Blaustrumpf.
blue laws Look up blue laws at Dictionary.com
1781, severe Puritanical code said to have been enacted 18c. in New Haven, Connecticut; of uncertain origin, perhaps from one of the ground senses behind blues, or from notion of coldness. Or perhaps connected to bluestocking in the sense of "puritanically plain or mean" (see bluestocking, which is a different application of the same term; the parliament of 1653 was derisively called the bluestocking parliament). The common explanation that they were written on blue paper is not considered valid; pale blue paper was used for many old U.S. legal documents and there would have been nothing notable about its use in this case.