adj.
1.under the level of the ground
2.conducted with or marked by hidden aims or methods
3.used of independent armed resistance forces underground adv.
1.in or into hiding or secret operation
2.beneath the surface of the earth underground n.
1.a secret group organized to overthrow a government or occupation force
2.electric underground railway
Idiom of the Day
right on
that`s right, yes (indicates approval for something)
The man yelled "right on" every time the politician promised to lower taxes.
