1. put right; correct: "mistakes made now cannot be rectified later"
2. convert (alternating current) to direct current.
3. find a straight line equal in length to (a curve): "his methods of rectifying the cycloid"
4. purify or refine (a substance) by repeated or continuous distillation:"butyl lactate was rectified, and the purified butyl lactate was sequentially hydrolyzed"
Word Originlate Middle English: from Old French rectifier, from medieval Latin rectificare, from Latin rectus ‘right’.