A special purpose acquisition company (SPAC) is a blank-check company with no business operations, formed to raise capital through an initial public offering (IPO) for the purpose of effecting a merger or other forms of business combination with one or more target businesses (also known as de-SPAC), effectively taking the target companies public.
Source: Going Public: Business Combination with a SPAC vs. Reverse Merger with a Non-SPAC Shell Company