This is the 379th most frequent Hungarian word.
ugyan
"Ugyan" in Hungarian means "really," "indeed," or is used to express doubt or emphasis, like "come on" or "surely."
Here 'ugyan' expresses slight doubt or incredulity, initiating a rhetorical thought.
Ugyan, miért gondolod ezt?
Why do you think this, anyway?
In this context, 'ugyan' emphasizes the negation, adding a level of certainty or dismissal.
Te ugyan nem fogsz ilyet tenni.
You're not going to do such a thing, certainly.
Here 'ugyan' is part of a compound, implying sameness or similarity.