Wiktionary
n. An inflatable structure, often, but not always a castle, allowing people to bounce around inside.
Wikipedia
Inflatable castles (closed inflatable trampolines, bouncy houses, moon bounce, moonwalks, or CITs) are temporary inflatable structures and buildings and similar items that are rented for functions, school and church festivals and village fetes and used for recreational purposes, particularly for children. The growth in popularity of moonwalks has led to an inflatable rental industry which includes inflatable slides, obstacle courses, games, and more. Inflatables are ideal for portable amusements because they are easy to transport and store.
The name given to such structures varies. They have been marketed with such names as "Bounce House", "Bouncies","Moon Bounce", "Boingalow", "Astrojump", "Moonwalk", "Jolly Jump" and "Spacewalk". "Brinca brinca", another name commonly used by Latinos, is Spanish for "jump jump". The term "Jolly Jumps" is often used to describe the inflatable playground structure in rural areas and some areas in the Western United States, but the term is otherwise obsolete. "Bouncy Castle" or "Inflatable Castle" are used in Ireland, the UK, New Zealand and parts of Australia, and "Jumping Castles" in Australia, Canada, South Africa and Arizona in the United States.
Inflatable castles have been suggested as having some therapeutic value for children with certain sensory impairments, similar to ball pits.
Usage examples of "inflatable castle".
A giant, inflatable castle wobbled dramatically as a dozen children bounced around on the inside of it, caroming off the walls and one another with equal amounts of enthusiasm.