| Definition -
An affix that is placed within a morpheme.
1. In contrast to interfixes, which are placed between two morphemes to form a word.
Example - One of the few English infixes is -ma-, which is used jocularly to give words false-sophistication, as in sophistimacated and edumacated.
Oxford English Dictionary - The term's first citation is from 1881:
"The arguments establishing the … connection of the Cambojan and Malayan languages … based on the principle of modifying infixes."
(Nature XXIII. 271/1)