I. bluer
comparative of blue
II. blu·er ˈblüə(r) noun
( -s )
Etymology: blue (III) + -er
: one that works at or supervises bluing: as
a. : a worker who colors the metal parts of guns by immersing them in bluing chemicals or by heat-treating
b. : an auto worker who tests the seating of valves by rotating them after smearing them with a blue compound that will show up high spots