To dream of an uncle represents a substitute form of conscience. Your ability to choose between right and wrong or make an important decision that is influenced in some manner. An uncle is a sign that you aren't making the right choices for the right reasons.
Positively, an uncle may reflect important decisions that are driven by positive intentions or a heightened need to do what's right.
Negatively, an uncle may reflect poor decision making or negative influences over your choices. It may also reflect excessiveness in your choices.
Alternatively, an uncle represents a quality in yourself based on your most honest feelings about them. Ask yourself what memories or feelings stand out the most about them and see how that quality may apply to your own life.
Example: A young man dreamed of seeing his Uncle being evil and laughing at him. His most honest feeling about this Uncle was that he ate too much. In waking life he was regretting a decision he made and went too far with.