situated beneath the surface of the earth; subterranean.
no longer living; buried, as in a cemetery (usually used predicatively): All those who might have known about the incident are now belowground.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use belowground in a sentence
To find out what might be crawling belowground, Bruno Buzatto, of Macquarie University in Sydney and the University of Western Australia in Perth, and his colleagues lowered in cups baited with rotting leaf litter to attract hungry invertebrates.This eyeless millipede shattered the record for most legs | Kate Baggaley | December 17, 2021 | Popular-Science