From www.dictionary.com:
quote ( P ) Pronunciation Key (kwōt)
v. quot·ed, quot·ing, quotes
v. tr.
1. To repeat or copy the words of (another), usually with acknowledgment of the source.
2. To cite or refer to for illustration or proof.
3. To repeat a brief passage or excerpt from: The saxophonist quoted a Duke Ellington melody in his solo.
4. To state (a price) for securities, goods, or services.
v. intr.
To give a quotation, as from a book.
n.
1. Informal. A quotation.
2. A quotation mark.
3. Used by a speaker to indicate the beginning of a quotation.
4. A dictum; a saying.
*snip*
Usage Note: People have been using the noun quote as a truncation of quotation for over 100 years, and its use in less formal contexts is widespread today. Language critics have objected to this usage, however, as unduly journalistic or breezy. As such, it is best avoided in more formal situations. The Usage Panel, at least, shows more tolerance for the word as the informality of the situation increases. Thus, only 38 percent of Panelists accept the example He began the chapter with a quote from the Bible, but the percentage rises to 53 when the source of the quotation is less serious: He lightened up his talk by throwing in quotes from Marx Brothers movies.