A company with a market capitalization between $2 and $10 billion, which is calculated by multiplying the number of a company''''s shares outstanding by its stock price. Mid cap is an abbreviation for the term "middle capitalization".
Taobiz explains Mid Cap
As the name implies, a mid cap company is in the middle of the pack between large cap and small cap companies.
Keep in mind that classifications such as large cap, mid cap and small cap are only approximations that change over time. Also, the exact definition of these terms can vary among the various participants in the investment business.