Webster's English Dictionary

grade

1. grade \'gra-d\ n [F, fr. L gradus step, degree; akin to L gradi to step, 
   go, Lith Xgridyti to go, wander 1a1: a stage in a process  1a2: a position 
   in a scale of ranks or qualities  1b: a class organized for the work of a 
   particular year of a school course  1c: a military or naval rank  1d: a 
   degree of intensity in illness {~ Iii carcinoma}  2a: a class of things of 
   the same stage or degree  2b: a mark indicating a degree of accomplishment 
   in school  2c: a standard of food quality {prime-grade beef}  3a: the 
   degree of inclination of a road or slope; also : a sloping  road 3b: a 
   datum or reference level; esp : ground level  3c: ELEVATION  4: a domestic 
   animal with one parent purebred and the other of inferior bre eding
2. grade vt 1a: to arrange in grades : SORT  1b: to arrange in a scale or 
   series  2: to level off to a smooth horizontal or sloping surface  3: to 
   improve by breeding females to purebred males  1a: to form a series  1b: 
   BLEND  2: to be of a particular grade