That book was about the dark side of the art world, which is a private, exclusive club that can be difficult to penetrate.
How secure could the border possibly be if 5-year-olds can penetrate it?
This provides a golden opportunity for the Taliban to infiltrate and penetrate wherever and when they wish.
If you want to penetrate the brain of a listener, wrap the information in things they care about.
A consortium of journalists has for months attempted to penetrate offshore banking secrecy.
It is dark as pitch within, for light cannot penetrate the mud with which the wood-work is liberally daubed.
Into the darker secrets of the Book of Wishes we will not penetrate.
For the moment there was not much danger, for no enemy craft was likely to penetrate so far north.
Nowadays, when one strives to penetrate things one is confounded.
If this 'skin' is removed, rain will penetrate the material and under the influence of frost may cause rapid disintegration.
1520s, from Latin penetratus, past participle of penetrare "to put or get into, enter into," related to penitus "within, inmost," penus "innermost part of a temple, store of food," penates "household gods." Related: Penetrated; penetrating.