libesting
Telling a lie is usually considered negative. A lie's usual intent is to defame (libel-written) or to deceive but it is always to give a false impression. Libesting (also spelled lybesting) is the act of lying in order to give a false impression of something being much, much better than it actually is. For instance, if a grandparent takes a child to the zoo and then returns that evening to host a family dinner and states, "I took my grandchild to the zoo today and I swear he was the most well-behaved child at the entire zoo for the entire day!" Well, you have heard of this because a lot of parents and grandparents do it--now you know the actual term for the gross exaggeration often used by a parent or grandparent to give a positive false impression.
It is libesting to give a positive false report about how perfect the weather was on a vacation during which there was inclement weather most of the time.