1. Under the level of the ground
   "belowground storage areas"
   - underground 
2. Underneath the ground
   "most of his friends are now belowground"

See also: buried, inhumed, interred, subsurface

• guidable
• guidance
• guidance device
• guidance system
• guide
• guide dog
• guide fossil
• guide on
• guide rope
• guidebook
• guided
• Guided Bomb Unit-28
• guided missile
• guided missile cruiser
• guided missile destroyer
• guided missile frigate
• guideline
• guidepost
• guider
• guideword
• guiding
• guiding light
• guild
• sauceboat
• saucepan