li·brar·y / ˈlīˌbrerē; -brərē/ • n. (pl. -brar·ies) a building or room containing collections of books, periodicals, and sometimes films and recorded music for people to read, borrow, or refer to: a school library [as adj.] a library book. ∎  a collection of books and periodicals held in such a building or room: the Institute houses an outstanding library of 35,000 volumes on the fine arts. ∎  a collection of films, recorded music, genetic material, etc., organized systematically and kept for research or borrowing: a record library. ∎  a series of books, recordings, etc., issued by the same company and similar in appearance. ∎  a room in a private house where books are kept. ∎  (also software library) Comput. a collection of programs and software packages made generally available, often loaded and stored on disk for immediate use.

library See program library, link library, DLL, optical disk library, tape library.

library XIV. — (O)F. librairie (now only ‘bookshop’) — Rom. *librārīa, alt. of L. librāria bookseller's shop, sb. use of librārius pert. to books, f. liber, libr— book; see -ARY, Y2.
So librarian †scribe XVII; keeper of a library XVIII. f. L. librārius + AN.

library (gene library) A random collection of cloned (see CLONE) DNA fragments in a number of vectors that ideally includes all the genetic information of that species.

library (gene library) A random collection of cloned (see CLONE) DNA fragments in a number of vectors that ideally includes all the genetic information of that species.