1)Over indulgence in anything; most often associated with food. It is also the excessive wasting of food/items and with holding from those who need it. Often it leads to lack of 'living' and a 'lifeless' life, or most of the time, to death and eternal torture in hell.
Gluttony is considered one of the seven deadly sins. Each sin is associated with a 'devil' and gluttony's is Beelzebub.
2)The unintelligent homunculus in Fullmetal Alchemist/Hagaren, Gluttony falls to his stereotype by excessive eating.
Although Gluttony is one of the Seven Deadly Sins, it is not considered as dangerous as Pride