penetrate

American Heritage® Dictionary of the English Language, Fourth Edition

1. v. To enter or force a way into; pierce.
2. v. To enter into and permeate: The insistent rhythm of piano practice penetrated each room of the house.
3. v. To cause to be permeated or diffused; steep.
4. v. To insert the penis into the vagina or anus of.
5. v. To enter (an organization, for example), usually surreptitiously, so as to gain influence or information; infiltrate.
6. v. To enter and gain a share of (a market): penetrated the home-computer market with an affordable new model.
7. v. To grasp the inner significance of; understand.
8. v. To see through: keen eyes that penetrate the darkness.
9. v. To affect deeply, as by piercing the consciousness or emotions.
10. v. To pierce or enter into something; make a way in or through something.
11. v. To gain admittance or access.
12. v. To gain insight.

Century Dictionary and Cyclopedia

1. To pierce into or through; enter and make way into the inner or interior parts of: as, the rays of light penetrated the thick darkness of the cave.
2. To enter and affect deeply; influence; impress; hence, to enter and become part of; permeate: as, to be penetrated with a sense of gratitude.
3. To arrive at the inner contents or the meaning of; see through; discern; discover: as, to penetrate a mystery; to penetrate a design.
4. Synonyms Penetrate, Pierce, Perforate, Bore through, Transfix. Penetrate may mean no more than to make entrance into, and that slowly or with some difficulty, or it may have the meaning of pierce. Pierce means to penetrate deeply and quickly, and therefore presumably, although not necessarily, with some sharp instrument. (See Heb. iv. 12.) Perforate and bore through mean to make a hole through, the former generally expressing the making of a smaller hole, the latter expressing sustained labor or slowness: as, the book-worm perforates leather binding; the carpenter bores through a beam; a bullet perforates or pierces the body. To transfix is to pierce through, the instrument remaining in that which is transfixed: as, to transfix a bird with an arrow; to transfix a butterfly with a pin.
5. To enter by piercing; pass, as a piercing instrument; enter and make way; reach by piercing: literally or figuratively: usually followed by to or into.

Wiktionary

1. v. Manage to enter into.
2. v. figuratively To achieve understanding despite (some obstacle thereto).
3. v. To insert a penis into an opening, such as a vagina or anus.
4. v. To infiltrate the enemy to gather intelligence.

GNU Webster's 1913

1. v. To enter into; to make way into the interior of; to effect an entrance into; to pierce.
2. v. To affect profoundly through the senses or feelings; to touch with feeling; to make sensible; to move deeply.
3. v. To pierce into by the mind; to arrive at the inner contents or meaning of, as of a mysterious or difficult subject; to comprehend; to understand.
4. v. To pass; to make way; to pierce. Also used figuratively.

WordNet 3.0

1. v. enter a group or organization in order to spy on the members
2. v. insert the penis into the vagina or anus of
3. v. come to understand
4. v. pass into or through, often by overcoming resistance
5. v. spread or diffuse through
6. v. make one's way deeper into or through
7. v. become clear or enter one's consciousness or emotions