| a screen or mat covered with a dark material for shielding a camera lens from excess light or glare. |
| a gadget; dingus; thingumbob. |
rarefaction rar·e·fac·tion (râr'ə-fāk'shən)
n.
A decrease in density and pressure in a medium, such as air, caused by the passage of a sound wave.
rarefaction (râr'ə-fāk'shən) Pronunciation Key
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