# Multiple Hosts:

    define service{
        host_name        HOST1,HOST2,HOST3,...,HOSTN
        service_description    SOMESERVICE
        other service directives ...
        }

# All Hosts In Multiple Hostgroups:

    define service{
            hostgroup_name        HOSTGROUP1,HOSTGROUP2,...,HOSTGROUPN
            service_description    SOMESERVICE
            other service directives ...
            }

# Excluding Hosts:

    define service{
        host_name             HOST1,HOST2,!HOST3,!HOST4,...,HOSTN
        hostgroup_name                HOSTGROUP1,HOSTGROUP2,!HOSTGROUP3,!HOSTGROUP4,...,HOSTGROUPN
        service_description   SOMESERVICE
        other service directives ...
        }