1a room or building for the display or sale of works of art:an art gallerythe National Gallery
a collection of pictures:an extensive gallery of colour photographs
2a balcony or upper floor projecting from an interior back or side wall of a hall or church, providing space for an audience or musicians:in the minstrels' gallery, a string orchestra plays themes from film soundtracks
(the gallery) the highest balcony in a theatre, containing the cheapest seats.
a group of spectators, especially those at a golf tournament:he lashed a two-iron on to the green, bringing gasps from the gallery
3a long room or passage, typically one that is partly open at the side to form a portico or colonnade.
a horizontal underground passage, especially in a mine:long underground galleries of 3 km or more made it possible to mine under the sea
play to the gallery
act in an exaggerated way in order to appeal to popular taste.
