1) Clinical research 2) Decrease 3) Defence mechanism 4) Diminution 5) Diversionary tactic 6) Minimization 7) Reduction 8) Step-down 1) Minimization 
[clinical trials] Minimisation is a method of adaptive stratified sampling that is used in clinical trials, as described by Pocock and Simon. The aim of minimisation is to minimise the imbalance between the number of patients in each treatment group over a number of factors. Normally patients would be allocated to a treatment group randomly...[psychology] Minimisation is a type of deception involving denial coupled with rationalisation in situations where complete denial is implausible. It is the opposite of exaggeration. Minimization – downplaying the significance of an event or emotion - is a common strategy in dealing with feelings of guilt. Words associated with minimisati...
see reduction
This term is often used to mean reducing the amount of waste we produce in the first place