placid

Adjective

• not easily irritated
  • an equable temper
    
  • not everyone shared his placid temperament
    
  • remained placid despite the repeated delays
    

• (of a body of water) free from disturbance by heavy waves
  • a ribbon of sand between the angry sea and the placid bay
    
  • the quiet waters of a lagoon
    
  • a lake of tranquil blue water reflecting a tranquil blue sky
    
  • a smooth channel crossing
    
  • scarcely a ripple on the still water
    
  • unruffled water
    

Related words

• Synonyms: 
  equable , even-tempered , good-tempered , quiet , still , tranquil , smooth , unruffled