1An imagined semblance of a man (or a man's face) in the disc of the (full) moon; (hence) the mythical person suggested by this semblance, supposed to dwell in the moon.
Patterns seen in the disc of the moon have in the past been variously stylized as a man leaning on a fork and carrying a bundle of sticks, or as a man with his dog and a thorn bush; see Brewer's Dict. Phrase & Fable (1870). In modern times the man in the moon is more usually figured as a man's face, either formed by the disc of the full moon or as a profile formed by the crescent moon.
2"no more than the man in the moon" and variants: no more than anyone, not at all.
Middle English. From man + in + the + moon. Inhabitants of the moon were postulated in ancient Greek and Hellenistic Greek texts; for closer analogies to the English phrase, compare German der Mann im Mond, French le visage de la lune, Dutch het mannetje in de maan, and post-classical Latin rusticus in luna; an early and influential attestation of the last from a British source is.