(Kansai) Sentence-final particle used for emphasis.

沼: swamp

沼間: a surname

非ず: (archaic, possibly obsolete) no, wrong / 非ず: (archaic, possibly obsolete) never mind

looks like, smacks of

平安: peaceful

(deictically) that one near you (near the addressee) / (anaphorically) the one we are talking about (either the speaker or the addressee knows) / that of (used only in writing)

formal form of せる

冪: (mathematics) power

inflected form of べし