| gen. |
fag; fag away; grub; hammer away (над чем-либо); peg; beaver (обыкн. beaver away); plod; plod away (над чем-либо – at something Anglophile); drudge (над ч.-либо – at something Anglophile); sweat away (at ... – над ... Alex_Odeychuk); grub away; peg away; dig (над чем-либо); plow; grub along (В.И.Макаров); grub on (В.И.Макаров); peg at (В.И.Макаров); peg away at (В.И.Макаров); plod at (В.И.Макаров); slog at (В.И.Макаров); slog away (В.И.Макаров); pour over (To examine, study, or read with intense, careful attention.  thefreedictionary.com KatrinSava); tinker (Sergei Aprelikov); plug away (with something); pore (over); sap (над чем-либо); plough |
