The _______ keyword in Go is used to retrieve the value for a given key from a map.

The 'map' keyword in Go is used to retrieve the value for a given key from a map. When accessing a value from a map, you provide the key inside square brackets ([]), similar to indexing an array or a slice. For example, if 'm' is a map and 'key' is the key you want to retrieve the value for, you would use 'm[key]' syntax. If the key exists in the map, this expression evaluates to the corresponding value; otherwise, it evaluates to the zero value for the value type of the map. Maps in Go provide a fast and efficient way to associate keys with values, making them a fundamental data structure in the language.