"forninst" has many other spellings, the most popular being
forenenst, foreninst, fornenst, ferninst, and fernenst
plus a variant form forenent, fornint, or fernent.
The meaning of this preposition is variably expressed as
over against, opposite to, near to, facing towards, and (by extension) figuratively against (i.e. opposed to).
It is chiefly a Scottish English word, carried however also by settlers to Ireland (particularly the North) and also -- whether directly from Scotland or, more frequently, by way of settlement from Ulster -- to the United States of America (where it is survives as a "regionalism").
Like many prepositions, it is a multiple compound in origin, made from adding fore to "anent", itself a compound of "on" and "even".
"Anent" -- meaning
over against, lying against, alongside, beside, in line with (but nowadays chiefly, and figuratively -- insofar as it is still used at all: about, concerning, in regard to)
-- has a very low profile these days but is still occasionally used, as such archaisms often are, for jocular effect.
On + efn (on even) acquired its final t to become on-efent by a process of end-strengthening, but became on-e'ent (Scottish anent, where "an" regularly replaces southern English "on") by a contrary process of medial weakening. The further end-strengthening of anent into anenst is similar to that at work in such pairs as while/whilst and among/amongst.
http://p211.ezboard.com/FORNINST/fwordorigins...the above would seem to suggest 'gegenüber' as being closer
