{i} quality of being unclean or contaminated; state of being morally unclean or corrupt; insignificant material that should be removed; component or ingredient that spoils the purity of something
That which is, or which renders anything, impure; foul matter, action, language, etc
Impurities are substances that are present in small quantities in another substance and make it dirty or of an unacceptable quality. The air in the factory is filtered to remove impurities
An element added to the semiconductor substrate material (either germanium, silicon, or gallium arsenide) in the fabrication process to create a P-type or N-type region For germanium, the impurities are arsenic and bismuth For silicon, the impurities are boron, phosphorus, and aluminum and for gallium, arsenic and phosphorus