WordNet sense 1 (able to be passed or traversed or crossed):

passable

WordNet sense 2 (able to be negotiated or arranged by compromise):

on the table

WordNet sense 3 (capable of being changed):

flexible

WordNet sense 4 (legally transferable to the ownership of another):

assignable, conveyable, transferable, transferrable

WordNet sense 5 (transferable to another owner):

alienable