The term "close season" refers to a period of time when hunting or fishing is prohibited. The opposite of a close season can be an open season, which indicates that hunting or fishing is legal and permitted during a certain period. Another antonym for close season is year-round hunting or fishing, which means that there is no restricted period of time for these activities. The term "unrestricted season" can also serve as an antonym for close season. In simpler terms, an antonym for close season refers to a time when hunting or fishing is allowed and unrestricted.