WordPress at a glance
action is not described

rest_delete_(taxonomy) action-hook . WP 4.7.0

Fires after a single term is deleted via the REST API.

The dynamic portion of the hook name, $this->taxonomy, refers to the taxonomy slug.

Usage

add_action( 'rest_delete_(taxonomy)', 'action_function_name_1946', 10, 3 );
function action_function_name_1946( $term, $response, $request ){
	// action...
}
$term(WP_Term)
The deleted term.
$response(WP_REST_Response)
The response data.
$request(WP_REST_Request)
The request sent to the API.

Where the hook is called

WP_REST_Terms_Controller::delete_item()
rest_delete_(taxonomy)
wp-includes/rest-api/endpoints/class-wp-rest-terms-controller.php 636
do_action( "rest_delete_{$this->taxonomy}", $term, $response, $request );

Where the hook is used (in WP core)

Does not used.