1) A regional spelling of ‘jamb’, used for the side post of a doorway or chimney-piece, derived from the French word for leg.
1546-7 Item for a mantyltre and ij jawmys and two stancions to his chymnay, vjd , York
1765 Chas Milner came & begun to Sett fire Jawms & make oven , Huddersfield
1775 the Jaums or side posts of doors , Halifax
1836 2 fire-place jawms 4ft each , South Crosland. The word has remained in use.