The word greed can mean intense and selfish desire for sometime, especially wealth,power,food. Being greedy can be Dangerous sometimes if one does not know how to handle it.
We can see how the greedy habit of ESAU turned into blessings for Jacob his younger brother. Some people think that Jacob was a cunning Man,who stole his brother blessings when Isaac their father wanted to bless him,but it was not like that.
Let us see what the Bible says about this(In Genesis chapter 25 verse 29-34).
Gen.25.29 - And Jacob sod pottage: and Esau came from the field, and he was faint:
Gen.25.30 - And Esau said to Jacob, Feed me, I pray thee, with that same red pottage; for I am faint: therefore was his name called Edom.
Gen.25.31 - And Jacob said, Sell me this day thy birthright.
Gen.25.32 - And Esau said, Behold, I am at the point to die: and what profit shall this birthright do to me?
Gen.25.33 - And Jacob said, Swear to me this day; and he sware unto him: and he sold his birthright unto Jacob.
Gen.25.34 - Then Jacob gave Esau bread and pottage of lentiles; and he did eat and drink, and rose up, and went his way: thus Esau despised his birthright.
Jacob his younger brother knew the important of having the birthright. He knew that the only thing which can make him to qualify for the blessings us to get the birthright from his brother. Esau on the other hand was a person who didn't know the important of the birthright,Jacob told him to sell his birthright to him and he(Esau)said that WHAT PROFIT SHALL THIS BIRTHRIGHT DO UNTO ME?This his statement tells us that he didn't value the birthright and he sold it to his brother (Jacob)even with swearing and Jacob gave him pottage and Esau went his way, thinking that he had eat Jacob food just like that.He went his way.
We could see in chapter 27 how Esau suffered the consequences of his action. He missed the blessings and Jacob obtained it. He(Esau) would have inherited the blessings no matter what if he still kept his birthrights.That is the reason why till today we have The God of Abraham, Isaac and Jacob and not Esau.
Being greedy negatively for something might be risk. You can be greedy for good things and get it.