strict

adjective

1. 1

   severe and unremitting in making demands

   an exacting instructor

   a stern disciplinarian

2. 2

   rigidly accurate; allowing no deviation from a standard

   rigorous application of the law

   a strict vegetarian

3. 3

   characterized by strictness, severity, or restraint

4. 4

   incapable of compromise or flexibility

5. 5

   (of rules) stringently enforced

   hard-and-fast rules