noun
branch store; temporary shop; pop-up store
A store or sales outlet set up temporarily, often in a department store event space, station building, or other location away from the main shop.
デパートの催事場に有名和菓子店の出張店が出ていた。
A famous Japanese confectionery had a temporary branch in the department store's event space.
催事出店 refers to the act of setting up a temporary shop at an event, often used in business contexts.
Compound of 出張 (business trip, going out to do business) and 店 (store, shop).