To cause (a liquid) to pass through something by filtration.
To cause to penetrate in this way.
To invade or penetrate a tissue or organ.
To surreptitiously penetrate, enter or gain access to.
To send (soldiers, spies, etc.) through gaps in the enemy line.
To pass through something by filtration.
To move from a vein, remaining in the body.
Any undesirable substance or group of cells that has made its way into part of the body.
To spill or pour out, because of a leak.
To be revealed (especially, of information intended to be kept secret).