"one who or that which opposes or withstands;" see resistor. In modern use this seems to more usual spelling in reference to persons rather than devices.
Entries linking to resister
resistor n.
late 14c., resistour, resister, "one who resists or hinders, one who prevents something from happening;" 1580s, "that which resists;" agent noun in Latin form from resist. In 19c., at least in U.S., resister seems to be the more usual spelling, and was used even in the science of electricity from 1759, though since c. 1900 that device has been a resistor and resister tends to refer to "person who resists" in some way.