[suhn-blok] 
| 1. | a substance that provides a high degree of protection against sunburn, often preventing most tanning as well as burning, as by obstructing the penetration of ultraviolet rays. |
| 2. | a lotion, cream, etc., containing such a substance. |
| sunblock also sun block (sŭn'blŏk') n. A preparation that prevents sunburn by filtering out the sun's ultraviolet rays, often purported to offer more protection than a sunscreen. |
sun block n.
A preparation, as of PABA, that prevents sunburn by filtering out the sun's ultraviolet rays, usually offering more protection than a sunscreen.
