The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
- One who holds an office or place, especially:a. One who acts as a deputy or proxy.b. One who holds an appointed office in a government.
- In a mathematical or logical expression, a symbol that may be replaced by the name of any element of a set.
- In the decimal form of a number, a digit that is not significant.