"expansion slot." YourDictionary, n.d. Web. 07 June 2018. <http://www.yourdictionary.com/expansion-slot>.
expansion slot. (n.d.). Retrieved June 07th, 2018, from http://www.yourdictionary.com/expansion-slot
(plural expansion slots)
A receptacle inside a computer or other electronic system that accepts a printed circuit board. The number of slots determines future expansion. See PC data buses, expansion port and expansion card.