study

A state of deep contemplation or rumination, as of a reverie, daydream, or meditation. It originally meant a melancholic or depressed mood or state (dating from at least the 1500s), but has since largely lost that association. It is usually preceded by "in a." Meredith sat at her desk in a brown study, carefully planning how to word her thesis proposal.

A person who can learn new material quickly. Primarily heard in US. You daughter is making great progress in her piano leassons—she's really a quick study.

a person who is quick to learn things. (Compare this to slow study.) Jane, who is a quick study, caught the joke immediately and laughed before everyone else.

a person who is slow to learn things. (Compare this to a slow study.) Fred, who is a slow study, never caught on to the joke.

to try to learn in preparation for an examination. I have to study for my calculus exam. Have you studied for your exam yet?

to learn all one can about someone or something. I have to study up on Abraham Lincoln in preparation for my speech. John studied up on seashells.

someone who is able to learn things quickly He's a quick study and easily grasps all the details of a discussion.

Daydreaming or deeply contemplative, as in Margaret sits in the library, in a brown study. This term dates from the late 1500s, and although by then in a study had long meant "lost in thought," the reason for adding brown is unclear. Moreover, the present idiom also is ambiguous, some holding that it denotes genuine thoughtfulness and others that it signifies absentmindedness.