Cunning

describes people who are clever at planning something so that they get what they want, especially by tricking other people, or things that are cleverly made for a particular purpose

a cunning plan/ploy

He's a very cunning man

 

 

 

 

 

Conservation

the protection of plants and animals, natural areas, and interesting and important structures and buildings, especially from the damaging effects of human activity

wildlife conservation

a conservation area

 

carefully using valuable natural substances that exist in limited amounts in order to make certain that they will be available for as long a time as possible

the conservation of coal/gas/oil reserves

Energy conservation reduces your fuel bills and helps the environment