A lie is the intentional act of denying a truth the liar knows to be true, whereas dishonesty can occur without lying. One can also be honest without being able to tell the truth. One can also lie while being honest and telling the truth. This is a fun discussion for me.
All language, at its most fundamental level, is a lie. If I use the word Elephant, a particularly large, four legged African, sometimes Asian, animal comes to mind. However, an Elephant is not an Elephant. Elephant is a word one group of people use as a verbally symbolic reference to this creature. Since all words are inherently engaged in the act of dying a known truth, that the word is not the thing, everyone is a liar.
The line between a lie and being dishonest is very, very fine. I'm not sure how to approach these differences at this time, but I'll get around to it.
From my little spot on this planet, all I can say about Truth is that it is beyond words and that Truth exists as a place of knowing. The Truth is felt through and through and impossible to articulate.