IPA: /ˈɡraʊndˌbɜrst/
KK: /ˈgraʊndˌbɜrst/
An explosion that occurs when a bomb or nuclear warhead impacts the ground.
The groundburst caused significant damage to the surrounding area.
Groundburst is formed from "ground" (from Old English "grund", meaning the surface of the earth) and "burst" (from Old English "berstan", meaning to break open or explode). The word describes an explosion that occurs at or near the surface of the earth.
Think of the 'ground' as the surface where something 'bursts' or explodes — that's why groundburst refers to an explosion happening at the earth's surface.
No commonly confused words.