Definition of "infix" [in•fix]

• To fix in the mind; instill. (verb-transitive)
• Linguistics To insert (a morphological element) into the body of a word. (verb-transitive)
• Linguistics An inflectional or derivational element appearing in the body of a word. For example, in Tagalog, the active verb sulat "write” can be converted to a passive, "written,” by inserting the infix -in-, yielding sinulat. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "An infix operator is an operator that is expressed using a mathematical notation called infix notation."
• "It is one of the only, if not the only words, that can be used as an "infix" "Fanfuckingtastic"."
• "An English teacher would tell you an 'infix' is a word more rarely an entire phrase inserted in the middle of another word to modify it."