'infix notation' definitions:

Definition of 'infix notation'

From: WordNet
noun
A notation for forming mathematical expressions using parentheses and governed by rules of operator precedence; operators are dispersed among the operands

Definition of 'infix notation'

From: GCIDE
  • infix notation \in"fix no*ta"tion\, n. (Computers) A notation for commands or instructions in which the operator is inserted between the terms on which it operates. Contrasted with prefix notation and postfix notation.