voracious: applies especially to habitual gorging WITH what satisfies an appetite: teenagers are often ~ eaters.  （gorge大吃，吃到哽噎爆裂implies glutting to the point of bursting and choking吃撑到好像要哽噎爆裂，如gorged themselves with chocolate他们大吃巧克力，glut出现在下一个词，表示大吃到哽噎implies an overeating that chokes and impedes，如bookstores glutted with diet books书店充斥着减肥书）


gluttonous: applies to delight in eating or acquiring things especially beyond the point of necessity or satiety: an admiral who had a ~ appetite for glory.     (satiety是satiate的名词，表示完全满足甚至过度满足implies complete or even excessive satisfaction，如the movie satiated their appetite for violence那部电影满足了他们对暴力的胃口）


ravenous: implies excessive hunger and suggests violent or grasping methods of dealing with whatever satisfies an appetite: football practice usually gives them ~ appetites.


rapacious: often suggests excessive and utterly selfish acquisitiveness or avarice: ~ land developers indifferent to the ruination of the environment.    （avarice贪婪成性，指痴迷于储藏财富、并强烈暗示吝啬implies obsessive acquisitiveness especially of hoardable wealth and strongly suggests stinginess，如avaricious thrift that left them morally bankrupt贪婪成性的吝啬使他们道德破产）   (攫：抓取；攫取: 掠夺，acquisitive和grasping都有攫取的意思)

voracious大吃的: 常指习惯性的吃很多东西，gluttonous贪婪贪吃: 指乐于贪食或获取，超出了必要满足界限，ravenous狂吃: 表示非常饥饿，好像要狂暴抓取食物，rapacious贪婪: 表示完全自私地贪婪攫取  


记忆方法: 1）首字母VGRR喂个肉肉<==贪吃


         2）贪吃的意思是过度贪婪mean excessively greedy.