IPA: /ˈʃɪftər/
KK: /ˈʃɪftɚ/
A person or thing that moves or changes position or state.
The shifter in the car allows the driver to change gears smoothly.
Shifter → It is formed from "shift" (from Old English *sciftan*, meaning to cause to move or change) and "-er" (meaning a person who). A shifter is a person or thing that causes a change or movement.
Think of someone who causes things to 'move' or 'change' — that's what a shifter does.