Can you explain what does wrath mean?
This is a great question. However, whenever you talk about definitions, you will need to realize a very important and fundamental point. Meanings of word are only partially located in the words themselves. Meaning is mostly located in the context. So, the word "wrath" can mean many things depending on the context.
For example, wrath can be purely negative in connotation if we say: "The wrath of the dictator knows no bounds, as he had every tenth person killed for something small."
If we change the context a bit, the word can take a different meaning. For example, Paul, in the New Testament says: "The wrath of God is being revealed against all ungodliness." From the context, we can say that wrath is rooted in the justice of God on account of ungodliness. From the perspective of those suffering unjustly, this wrath is good news. It is the fulfillment of their justice.
In light of these points, the context is key. Without the context, wrath is usually tantamount to anger and punishment.