Spool can mean one of the following: Spool, a System Peripheral Output On-Line. Spool, a usually low-flanged or unflanged cylinder on which thread, wire, cable, paper, film, or tape's wound for distribution or use. Bobbin, a cylinder or reel on which a quantity of thread, yarn or wire's wound for use in a particular machine or device. Spooling, Simultaneous Peripheral Off-line Output Listing, temporary data storage in computing. Spool, a shaft of a gas turbine engine. Spooling up usually re… (More on Spool)