Verb
(intransitive, especially of an animal, chiefly Canada, US) To escape into a burrow, hole, etc. when being hunted.
(figuratively, by extension, chiefly Canada, US) To hide from public view or sequester oneself, especially when authorities, members of the news media, or others are looking for one.
Source: en.wiktionary.orgI started working at the mines and the only thing that kept me from having to go underground was my matric. Source: Internet
Indeed, with proper engineering, a rail line could run along a street, then go underground, and then run along an elevated viaduct. Source: Internet
He was forced to go underground, as he had been under the Tsarist regime. Source: Internet
However, following the persecutions of Toyotomi Hideyoshi and the subsequent closing of Japan to foreigners, the Christians of Japan were forced to go underground to develop an independent Christian culture. Source: Internet
The first was to go underground, and to begin a violent, armed struggle against the state without attempting to organize or mobilize a broad swath of the public. Source: Internet
However, as in the case of so many other fields of activities, when they are banned, they go underground and continue to exist. Source: Internet