extender

noun

1. One who extends.

   “The public has learned to accept the services of physician extenders as a substitute for a qualified medical doctor, but the medical profession itself will, I daresay, continue to erect substantial barriers to any policy or effort that directly affects income.”

   “[Marc Jacobs] is a colonialist, an extender of brands, and in very good shape.”

2. Any of various substances designed to extend any of several properties of a material.

   ““Flour” routinely contained crushed stone or gypsum as a cheap extender.”

3. Any of various components designed to extend the length of a device.
4. Any substance added to food to bulk it out, with a higher protein content than a filler.

   “Soy protein is used as a meat extender.”

5. A runner, or quick-draw.
6. A phrase that extends an expression to include further members of a set, e.g. "and stuff", "or something".