I've never seen that definition in any dictionary.100% honesty means not holding anything back. If I only tell you 90% of the facts, I have not been 100% honest. It's not that hard a concept to grasp. And not being 100% honest is NOT the same as being DISHONEST. I've never once made such a claim.
However, tutors have 100% of the facts on the subject they are teaching. Do you think them dishonest because they teach what is needed, which may be 20% of those facts?