ゼン, ネン, しか, しか.り, しか.し, さ
sort of thing, so, if so, in that case, well
JLPT3 G4 S12 F401
Effectively a variant form of 難 (grill over a fire), with the distinction that in 難 it is 隹 a bird being grilled while in 然 it is 犬 a dog/beast → *burn*. *Thus*, *that's right*, *but*, *however*, and *as it is* are borrowed meanings.
[Full Kanji Etymology List]