post·​fix ˈpōs(t)-ˌfiks How to pronounce postfix (audio)
: characterized by placement of an operator after its operand or after its two operands if it is a binary operator compare infix, prefix

Word History


post- + -fix (as in prefix)

First Known Use

1973, in the meaning defined above

Time Traveler
The first known use of postfix was in 1973

Dictionary Entries Near postfix

Cite this Entry

“Postfix.” Dictionary, Merriam-Webster, Accessed 8 Dec. 2023.

Medical Definition


transitive verb
post·​fix (ˈ)pōst-ˈfiks How to pronounce postfix (audio)
: to treat again with a different fixative
the tissue was postfixed in 1 percent osmium tetroxide
postfixation noun
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