What does "rectify" mean?

Rectify: (Chem.) To refine or purify by repeated distillation or sublimation, by which the fine parts of a substance are separated from the grosser; as, to rectify spirit of wine.

Additional senses

  1. 2.(Com.) To produce ( as factitious gin or brandy) by redistilling low wines or ardent spirits (whisky, rum, etc.), flavoring substances, etc., being added. To rectify a globe, to adjust it in order to prepare for the solution of a proposed problem. See Amend.

Sources