WordWeb Online

1. With low volume
   "she spoke quietly to the child";
   - softly
    
2. With little or no sound
   "the class was listening quietly and intently"; "she was crying quietly"
    
3. With little or no activity or no agitation ('quiet' is a nonstandard variant for 'quietly')
   "her hands rested quietly in her lap"; "the rock star was quietly led out the back door";
   - quiet
    
4. In a restful manner
   "the streets are quietly sunny and still for the town is at mass";
   - restfully

Antonym: noisily, unquietly

Encyclopedia: Quietly