1.math: determine the length of;
rectify a curve
2.reduce to a fine, unmixed, or pure state; separate from extraneous matter or cleanse from impurities;
refine sugar
3.bring, lead, or force to abandon a wrong or evil course of life, conduct, and adopt a right one;
The Church reformed me
4.set straight or right;
remedy these deficiencies
5.make right or correct;
Correct the mistakes
6.convert into direct current;
rectify alternating current