strict

Adjective

• severe and unremitting in making demands
  • an exacting instructor
    
  • a stern disciplinarian
    
  • strict standards
    

• incapable of compromise or flexibility

• characterized by strictness, severity, or restraint

• (of rules) stringently enforced
  • hard-and-fast rules
    

• rigidly accurate; allowing no deviation from a standard
  • rigorous application of the law
    
  • a strict vegetarian
    

Related words

• Synonyms: 
  stern , exacting , rigid , nonindulgent , hard-and-fast , rigorous