[app. originally from BROWN in sense of gloomy; but this sense has been to a great extent forgotten. (The conjecture that brown might be the Ger. braune brow does not require serious notice.)]
A state of mental abstraction or musing: gloomy meditations (J.); serious reverie, thoughtful absent-mindedness (Webster); now esp. an idle or purposeless reverie.
1532. Dice-Play, 6. Lack of company will soon lead a man into a brown study.
1579. Lyly, Euphues (Arb.), 80. You are in some brown study, what colours you might best wear.
1607. Topsell, Serpents, 772. Nothing but sadnesse, and heavinesse of minde, brown-studies.
1693. Oxford-Act, 2. Oft woud the new created Sophister Where Boy cryd, want ye any Coffee, Sir? Start from brown-study.
1712. Steele, Spect., No. 286, ¶ 3. He often puts me into a brown Study how to answer him.
1871. Blackie, Four Phases, I. 13. He had been standing there in a brown study.