Im reading The Colloquia of the Hermeneumata Pseudodositheana which it has latin and its and translations.
poposci calciamenta et ocreas; erat enim frigus.
I asked for shoes and leggings; for it was cold.
In this context it is postpositive "for" in the sense of because.
And for etiam : which is in the book "learn latin in an ancient way"
diuturnus enim languor et senecta, quae saepe etiam languore deterior est, universam substantiam eius absumpserat.
For a long illness and old age, which often "even" worst than illness is, had consumed all his property.
But I think it depends in the context, for/enim the words has many different meanings