What is the meaning of the word "study"?

Definitions:

a composition intended to develop one aspect of the performer's technique noun
- a study in spiccato bowing
a room used for reading and writing and studying noun
- They knocked lightly on the closed door of the study.
a state of deep mental absorption noun
- I am in a deep study.
a written document describing the findings of some individual or group noun
- this accords with the recent study by Hill and Dale
be a student verb
- follow a course of study
learn by reading books verb
- We are studying geology in my room.
someone who learns quickly and easily, as the lines for a part in a play noun
- The new understudy is a quick study.
to think intently and at length, as for spiritual purposes verb
- I studied my options carefully.