adjective

• (Scotland law, now rare) Pertaining to the reduction of a decree etc.; rescissory.
• Causing the physical reduction or diminution of something.
• (chemistry, metallurgy, biology, economics) That reduces a substance etc. to a more simple or basic form.
• (now rare, historical) That can be derived from, or referred back to, something else.
• (now frequently derogatory) That reduces an argument, issue etc. to its most basic terms; simplistic, reductionist.