The surname Železnikar originates in the
place names Železniki and Železnica. It is formed using the suffix -ar
and originally denoted "one who dwells in that place or one who came
from that place." Derivation is also possible with -ar from the surname
Železnik or the place name Železniki to stress the difference between a
surname and a place name or with -ikar from the place Železno. The
surname Železnik can be formed with the suffix -ik from the place name
or name of hamlet Železno, etc., or taken from the word "Železnik"
meaning "suit of armour, cuirassier," "bench" and "a type of a plant"
(See Pleteržnik, II, 956). The surname Železen, though, originates in
the adjective "Železen" ("iron") and could have originally meant
"solid, of body or health." The surname Železinger is a Germanized form
of the surname Železnikar in which the German suffix -(ing)er has the
same formation function and meaning as the Slovene -(ik)ar.
This explanation is from a
series on the origin of Slovene names by Dr. Janez Bogataj appeared in
the quarterly magazine Slovenia. Unfortunately the magazine is
no longer being published.