Yes, it is! It is used e.g. in 'ten eerste' and 'ten tweede' (first; second, etc.).
Dat is ten eerste niet gewenst en ten tweede niet mogelijk. - First of all, that is not desirable and secondly not possible.
'Ten' is contraction between 'te' and 'den'. 'Den' is the dative form of 'de' (singular masculine and neuter). Even though we don't use the case system anymore, we still use some words, and this is one of them. :)