Definition of 'Semiconductor'
A materials product - usually comprised of silicon - which conducts electricity more than an insulator but less than a pure conductor, such as copper and aluminum. Semiconductors are usually very small and complex devices, and can be found in thousands of products such as computers, cell phones, appliances, and medical equipment.
Also known as "chips" or "semis".
Investopedia explains 'Semiconductor'
As semiconductors have evolved and become more powerful, they have propelled many industries forward into a technological age. They are still an expensive component in many devices, so their pricing and demand trends go a long way in determining the profit potential of companies that sell devices with semiconductors in them. Chips are made by the billions each year, and their sales & pricing trends are widely followed by analysts as a harbinger of technology-related profits.
Semiconductor makers often see "boom and bust" cycles based on the underlying demand for chip-based products. When times are good profit margins can run very high for chipmakers; when demand falls through however, chip prices can fall dramatically and have a major affect on many industries' supply chains.