-ern

Etymology
In form, from, , , (, , , , etc), from  (, etc), from  *-r- (probably from rebracketing of *nurþrōnijaz etc) + , whence also 🇨🇬, 🇨🇬, 🇨🇬 / 🇨🇬. In practice, possibly a back-formation from, , etc.

(Contrast the in, etc., which is related to .)

Etymology 2
Extended form of, generalised from such forms as , , , originally also , in which -er is derived from the stem or from the plural.

Suffix

 * 1) made of

Etymology 3

 * 1) Dative plural suffix for nouns that form the plural in  (with or without Umlaut) or whose plural form (not root) already ends in -er.
 * der Mann - den Männern
 * der Rechner - den Rechnern

Etymology 1
From, from.

Etymology 2
From.

Etymology 1
From the adjectival use of, from.

Etymology 2
Variant of.