[pen-i-truh
nt] 
| 1. | a person or thing that penetrates. |
| 2. | a compound that penetrates the skin, as a lotion or cream. |
| 3. | a substance that lowers the surface tension of water; wetting agent. |
| 4. | Zoology. a large nematocyst discharging a barbed thread that penetrates the body of the prey and injects a toxic fluid. |
| 5. | penetrating. |
[pen-i-trey-ting] | 1. | able or tending to penetrate; piercing; sharp: a penetrating shriek; a penetrating glance. |
| 2. | acute; discerning: a penetrating observation. |
| 3. | Surgery. noting a wound that pierces the skin, esp. a deep wound entering an organ or body cavity. |
| pen·e·trant (pěn'ĭ-trənt) adj. Penetrating; piercing: a penetrant wind from the north. n. Something that penetrates or is capable of penetrating. |