The best replacement for slot is round port.

The best alternatives to slot are rated as following:
★★★★★  round port
★★★  agp slot
★★★  socket
★★  pci slot
★★  aero port
★★  tray
★★  pci express
★★  groove
★  pci
★  timeslot
★  pcmcia
★  agp
★  flanker
  express card slot
  an expresscard slot
  pci-e slot
  simple slot
  5-in-1 media card reader slot
  pci express slot
  an expresscard® slot
  isa slot
  pcie slot
  pcmcia slot
  media card slot

Your alternative for slot is not listed? Suggest!
Speaking about slot, one probably shouldn't forget about box.

Other search terms related to slot and their ratings are:

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