a new, usually small business that is just beginning its operations, especially a new business supported by venture capital and in a sector where new technologies are used nounthe beginning of a new company or new product ExampleWe went into the red for the first time because of the costs for the start-up of our new subsidiary.a new, usually small business that is just beginning its operations, especially a new business supported by venture capital and in a sector where new technologies are used"It's unusual for a venture capitalist to be focused tightly on a set of companies with a common technology base, and even more unusual for the investment fund manager to be picking start-ups that will be built on a business he's currently running." [InformationWeek] the beginning of a new company or new product