To correct or adjust something that is wrong or not accurate. The technician was called in to rectify the issue with the computer system.
To purify or refine a substance, especially by repeated distillation. The chemist needed to rectify the alcohol to ensure its purity for the experiment.
To convert alternating current to direct current through a process of electrical rectification. The full-wave bridge rectifier is used to rectify the incoming AC into smooth DC.