Hermes

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The god of commerce, invention, cunning, and theft, who also served as messenger, scribe, and herald for the other gods.

from The Century Dictionary.

• noun In Greek myth, the herald and messenger of the gods, protector of herdsmen, god of science, commerce, invention, and the arts of life, and patron of travelers and rogues, son of Zeus (Jupiter) and Maia, born on Mount Cyllene in Arcadia.
• noun [lowercase; pl. hermæ (-mē).] In Greek antiquity, a head or bust supported upon a quadrangular base, which corresponds roughly in mass to the absent body, and often bears in front a phallus as an indication of the sex.
• noun The Egyptian god Thoth, as identified with the Greek Hermes.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Myth.) See mercury.
• noun (Archæology) Originally, a boundary stone dedicated to Hermes as the god of boundaries, and therefore bearing in some cases a head, or head and shoulders, placed upon a quadrangular pillar whose height is that of the body belonging to the head, sometimes having feet or other parts of the body sculptured upon it. These figures, though often representing Hermes, were used for other divinities, and even, in later times, for portraits of human beings. Called also herma. See Terminal statue, under Terminal.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• proper noun Greek mythology The herald and messenger of the gods, and the god of roads, commerce, invention, cunning, and theft.
• proper noun astronomy The planet Mercury when observed as an evening star.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun (Greek mythology) messenger and herald of the gods; god of commerce and cunning and invention and theft; identified with Roman Mercury