From BiblePortal Wikipedia

Webster's Dictionary [1]

(n.) A trope in which one word is put for another that suggests it; as, we say, a man keeps a good table instead of good provisions; we read Virgil, that is, his poems; a man has a warm heart, that is, warm affections.

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [2]

( Μετωνυμία , "Denominatio Nominispro Nomine Posita ," Quintillian, 8, 6, 23), a technical term in rhetoric designating a " trope, in which a word is used to express-a thing differing from its original meaning in kind" (E. D. Haven, Rhetoric, p. 78). Metonymies are a little bolder than synecdoches (q.v.), and, as Aristotle observes, may be employed either to elevate or to degrade the subject, according to the design of the author. The substance may be named for the quality, the cause for the effect, the precedent for the consequent, or the reverse, e.g. "Addison was smooth, but Prescott smoother." Here Addison means the writings of Addison;. smooth means pleasing to the ear. Both words are metonymic. " Always respect old age" a metonymy for aged people. Thus, "gray hairs" may stand for "old age," the name of Virgil for that of his writings, the "head" for the "intellect," and the "olive-branch" for "peace." Metonymies may be classified as follows:

(1.) The Sign For The Thing Signified , signum pro signato. Sword for war; Θρόνος for power ( Luke 1:32;  Hebrews 1:8); Ἀνατολή , Δυσμή , for east and west ( Matthew 2:3;  Luke 13:29;  Psalms 46:6); Red Tape , for the difficulties in obtaining the completion of a work that must pass the inspection of several officers; a Pen for literature-" The pen is mightier than the sword."

(2.) The Container For The Thing Contained , continens pro contento. "The Country is jealous of the City ." "The Army yielded, but the Navy resisted;" Οικος , world, for the human beings contained in the world ( Matthew 18:7;  John 1:10;  John 3:16-17); Κόσμος , the house, for domestics ( John 4:53;  Acts 10:2;  Acts 10:11;  Acts 10:14;  Acts 10:16).

(3.) A Cause May Be Put For An Effect, And An Effect For A Cause . " The Savage desolation of war." The Cause of the desolation is a savage spirit; here it is transferred to the effect. In an opposite transference, we may speak of Pale death. joyful Health , a Proud testimony. This is sometimes called a Transferred Epithet .

(4.) A Man May Be Named For His Works . Thus we speak of " Shakespeare," meaning his writings. " Blackstone," meaning his works on law. So the " Prophets" are referred to ( Mark 1:2;  Luke 16:29;  Luke 24:44;  Acts 8:28), meaning their writings. This is akin to personification (q.v.).