doubler

One who doubles.

An instrument for augmenting a very small quantity of electricity, so as to render it manifest by sparks or the electroscope.

A metal plate riveted or welded over a preexisting metal structural component to reinforce it and relieve the stress on the preexisting component, or to serve as a patch where part of the original structure has failed or been removed.

The mechanics fastened a doubler over the hole where the cracked section of the plane's skin had been cut out.

The airworthiness directive called for riveting a reinforcing doubler to the wing midspar web to keep the spar from buckling under flight loads.

Part of a distilling apparatus for intercepting the heavier fractions and returning them to be redistilled.

A blanket or felt placed between the fabric and the printing table or cylinder.

A tenement house having two families on each floor.

A biplane aeroplane or kite.