penetrate
v.v. to enter or move into something, often by force. You use this when something goes deep inside a surface or a group.
v. to enter, pass through, or pervade; to make one's way into or through a substance, barrier, or group.
The arrow penetrated the thick wood.
The journalist tried to penetrate the tight circle of politicians surrounding the president.
The documentary aims to penetrate the complex layers of corporate bureaucracy to reveal the human cost of efficiency.
From Latin penētrātus, perfect passive participle of penētrō (“to put, set, or place within, enter, pierce, penetrate”) (see -ate (verb-forming suffix)), from penes (“within, with”) by analogy to intrō (“to go in, enter”). Compare French pénétrer.
The verb is transitive and takes a direct object.