From medieval Latin grossus ( "thick, fat") , which comes from crassus, a , um . 1st_ Fat Female . 2nd_ Sebum of animal and plant origin . It is a combination of glycerins with fatty acids. 3rd_ Fatty lubricant that can be organic, mineral or synthetic . 4th_ In lunfardo you are said 'fat' to something or someone ordinary, mersa, without class. Perhaps it is associated with food: the one that drips fat is supposed to be of low quality, and the one who consumes it is not exactly a gourmet, not even a guru.