Pen"e*tra`tion (?), n. [L. penetratio: cf. F. pénétration.] 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.

A penetration into the difficulties of algebra.

2. Acuteness; insight; sharp discoverment; sagacity; as, a person of singular penetration. Walpole.

Syn. -- Discernment; sagacity; acuteness; sharpness; discrimination. See Discernment, and Sagacity.

• The act of penetrating.
       Any penetration, however slight, is sufficient to complete the offense.