WordPress at a glance
function is not described

wp_delete_category() WP 2.0.0

Deletes one existing category.

No Hooks.

Return

true/false/Int/WP_Error. Returns true if completes delete action; false if term doesn't exist; Zero on attempted deletion of default Category; WP_Error object is also a possibility.

Usage

wp_delete_category( $cat_ID );
$cat_ID(int) (required)
Category term ID.

Code of wp delete category: wp-includes/taxonomy.php WP 5.2.2

<?php
function wp_delete_category( $cat_ID ) {
	return wp_delete_term( $cat_ID, 'category' );
}