Approximator
The Century Dictionary and Cyclopedia
noun.
One who approximates or comes near.
the GNU version of the Collaborative International Dictionary of English
noun.
One who, or that which, approximates.
Wiktionary, Creative Commons Attribution/Share-Alike License
noun.
Something that
approximates
Word Usage
"Law ordains universally that neither Man nor Woman shall be approached so closely as to destroy the interval between the approximator and the approximated."