improver

After small proprietors, however, rich and great farmers are in every country the principal improvers.

Act as a professional spelling and grammar corrector and  improver.

There I stayed till six months ago, when I obtained a situation as improver, as it is called, in a London office.

In addition to its use as a wine sweetener and a paint improver, lead offered even more benefits as a gasoline additive in the form of a compound known as tetraethyl lead.