It sounds like you're asking for a word that means "to use a necessary quality or behavior" and starts with the letters "i-e." However, there isn't a word that directly matches that description.
To help me understand, could you tell me:
* What is the context of this word? What are you trying to say?
* What kind of quality or behavior are you referring to?
* Is there another word you're trying to think of, but can't remember?
With more information, I can help you find the right word.