Do you fully understand the word "infeers"?

In the "How to Present Scientology to the World" lectures (also known as the "Organization Series Lectures"), there's a lecture called "A Postulate Out of a Golden Age," in which LRH says,

"Now, a person who is apt to be challenged by his peers or "infeers" is very apt to fly into the future for his very solid utterances."

However, "infeers" is not in the glossary at the back of the transcript, and the term is not defined in the Dianetics and Scientology Technical Dictionary.

Is "infeers" defined in any official Scientology publication? If not, how does one word-clear this word?