Meaning of UNDERGROUND in English

UNDERGROUND

adv., adj., n., & v.

--adv.

1. beneath the surface of the ground.

2 in or into secrecy or hiding.

--adj.

1. situated underground.

2 secret, hidden, esp. working secretly to subvert a ruling power.

3 unconventional, experimental (underground press).

--n.

1. an underground railway.

2 a secret group or activity, esp. aiming to subvert the established order.

--v.tr. lay (cables) below ground level.

Oxford English vocab.      Оксфордский английский словарь.