delete
https://{youraccountname}.api-us1.com/api/3/group/bulk_delete
Delete several user groups in a single request and move everything that referenced them to another group.
Users and deal groups belonging to the deleted groups are reassigned to the group given in to, and the deleted groups are removed from any automations they were assigned to. Parameters are sent as query string or form parameters, not as a JSON body; POST is accepted with the same parameters. from must be sent as an array, even when deleting a single group.