1) A joist.
1613 from Crosland parke, of Thomas Bayley 4 sommer trees and 80 jobbyes, Almondbury
1621 all my tymber, sparres, loose-boards, jobbies and gysts, Wibsey
1720 Paid for 4 gobbys from Middleton, Bradford. The Halifax historian Watson had ‘jobby’ in his list of local words in 1775, defining it as a joist or piece of timber fastened into the sommer of an house.