plumb Synonyms

perpendicular plummet plumb bob measure plum vertical plumb line determine penetrate clean straight explore fathom straight up investigate gauge probe upright thoroughly straightly standing scrutinize sheer sheerly sinker smack sound spang square squarely totally true understand caliper in line slap bang take soundings on end plumb rule set square unswervingly quantify utterly figure out upward vertically verify verticality stand up scrutinise