beneath the surface of the ground
miners working underground
situated beneath the surface of the ground
an underground car park
an underground railway, especially the one in London
travel chaos on the Underground
a group or movement organized secretly to work against an existing regime
the French underground
a group or movement seeking to explore alternative forms of lifestyle or artistic expression
the late sixties underground
lay (cables) below ground level
sections of electricity line had been undergrounded
the environment secretary ordered the undergrounding of cables