overground

over|ground /'oʊvə^rgraʊnd/
The adjective is pronounced /'oʊvə^rgraʊnd/ The adverb is pronounced /'oʊvə^rgr'aʊnd/
[ADJ] ADJ n
In an overground transport system, vehicles run on the surface of the ground, rather than below it. (BRIT)
Bus routes and railways, both overground and underground, converged on the station.
≠ underground
[ADV]
Overground is also an adverb.
There are plans to run the line overground close to the village of Boxley.