(1):

(n.) One who speaks several languages.

(2):

(n.) A book containing several versions of the same text, or containing the same subject matter in several languages; esp., the Scriptures in several languages.

(3):

(a.) Versed in, or speaking, many languages.

(4):

(a.) Containing, or made up, of, several languages; as, a polyglot lexicon, Bible.