- a substance added to another substance, as to paint or food, to increase its volume or bulk: to add cereal and soy protein to hamburger as extenders.
- See under converter (def. 8).
- a person or thing that extends
- a substance, such as French chalk or china clay, added to paints to give them body and decrease their rate of settlement
- a substance added to glues and resins to dilute them or to modify their viscosity
- a substance added to elastomers to assist the plasticizer
- the part of certain lower-case letters that extends either above (the ascender) or below (the descender) the body of the letter
