Question

Almost everybody has had the feeling of knowing the answer to a question, but not being quite able to say it. this is called the "tip-of-the-tongue phenomenon, and is a failure of:

Answer 1

I believe the answer is: Failure of retrieval
Failure of retrieval refers to the situation when we couldn't bring out a certain stored information without specific cues.
The most likely cause of the failure of retrieval is due to the missing stimuli that exist when we remember the information on the first time.