- Penetration Pen"e*tra`tion, n. [L. penetratio: cf. F.
1. The act or process of penetrating, piercing, or entering;
also, the act of mentally penetrating into, or
comprehending, anything difficult.
And to each in ward part, With gentle penetration, though unseen, Shoots invisible virtue even to the deep. --Milton. [1913 Webster]
The Collaborative International Dictionary of English. 2000.