gallery (Noun) — Spectators at a golf or tennis match.
gallery (Noun) — A porch along the outside of a building (sometimes partly enclosed).
gallery (Noun) — A room or series of rooms where works of art are exhibited.
gallery (Noun) — A long usually narrow room used for some specific purpose. ex. "shooting gallery"
gallery (Noun) — A covered corridor (especially one extending along the wall of a building and supported with arches or columns).
gallery (Noun) — Narrow recessed balcony area along an upper floor on the interior of a building; usually marked by a colonnade.
gallery (Noun) — (mining) a horizontal (or nearly horizontal) passageway in a mine. ex. "they dug a gallery parallel with the vein"