have been infixing

• present perfect progressive

  present perfect progressive

  Used to describe an action that began in the past, has continued continuously, and is still in progress.

  of infix.
  infix

  noun

  a morpheme or an entire word that is inserted within the body of another word or element, as Latin m in accumbō “I lie down,” as compared with accubuī “I lay down.”

More Suggestions

• nitrogen-fixing