exacting

adjective

1. 1

   requiring precise accuracy

   an exacting job

   became more exigent over his pronunciation

2. 2

   severe and unremitting in making demands

   an exacting instructor

   a stern disciplinarian

3. 3

   having complicated nutritional requirements; especially growing only in special artificial cultures

   fastidious microorganisms

   certain highly specialized xerophytes are extremely exacting in their requirements