Definition of swither:
(v) :
(Scotland, Northern England) To be indecisive or in a state of confusion; to dither.
(n) :
(chiefly Scotland, Northern England) A state of indecision or confusion; a panicked state; a flap, fluster, or dither.
(v) :
(dialectal, figurative) To smart, ache; tingle
(v) :
(dialectal) To burn, scorch, singe.
(v) :
(dialectal) To burn slowly, melt (as a candle), sweal
(n) :
(dialectal) A great heat; a scorching, singeing