1. the act of setting in operation (Freq. 1) - repeated shutdowns and startups are expensive • Derivationally related forms: start up • Hypernyms: beginning, start, commencement 2. the act of starting a new operation or practice - he opposed the inauguration of fluoridation - the startup of the new factory was delayed by strikes • Syn: inauguration • Derivationally related forms: start up, inaugurate (for: inauguration) • Hypernyms: beginning, start, commencement