1) Apply a curve to 2) Assign to new categories 3) Change a letter 4) Curve the results 5) Go over a test paper again 6) Go over test papers again 7) Make an F a D 8) Mark again 
Regrade , The differential between kerosene and gasoil. trades actively in various months other than q412 where has not been a bid within 20 cents of value since the late 1990s ...
• (v. i.) To retire; to go back.
<geology> To intentionally reconfigure the elevations and slopes on a parcel of land by means of surveying technology and construction equipment. ... (16 Mar 1998) ... 
Re·grade' intransitive verb [ Latin re- re- + gradi to go. Confer Regrede . ] To retire; to go back. [ Obsolete] W. Hales.