She cried uncle?

I was watching Heroes, and a women in the scene said

"I want my lawyer now"
and the detective said
"bla bla bla bla.... tell me who wants revenge!"
and his colleague said
"Stand down man, she cried uncle"

what does she cried uncle mean?

and why that detective said "who wants revenge" not "who wants the(an) revenge?" why the article can be omitted?

Cry uncle = to admit defeat, to surrender, to give up (http://www.bartleby.com/59/4/saycryuncle.html, http://www.worldwidewords.org/qa/qa-say1.htm, etc - google it).

Revenge is not countable (can't say a revenge, some revenges), and in this case it is also abstract - he is not referring to a specific revenge (e.g. the revenge of nature), so he is right not to use an article. It's how you'd say "I want justice", "I need love" etc.

Note that "to cry uncle" can be both literal and metaphorical. When kids are "roughhousing" -- basically, playful informal wrestling or fighting, usually with no intention to harm the opponent -- one will occasionally manage to grab the other's arm or something and twist it in a painful way, until the other party says "Uncle! Uncle!", conceding the fight.

But unless we're clearly talking about this kind of roughhousing context, the usage is almost always metaphorical, even in other fighting contexts. For instance, if it's said that a boxer cried uncle in a boxing match, he probably didn't actually cry out "Uncle! Uncle!". He just probably "went down without a fight".

- Kef

Why not Aunt because Uncle is physically more strong. But in western societies, there is no such distinction made. Both women and men are equal. Both genders are fighting wars together. So why cry "Uncle"??

Because it's not how the expression goes. You're trying to apply logic to something that is inherently independent from logic. In language we can always ask, "Why not this? Why not that?" But the answer is always the same: "Because we just don't say that."

- Kef