grind

grind verb [ T ] uk/ɡraɪnd/ uspast tense and past participle ground grind verb [T]
(MAKE SHARP)

to rub a blade against a hard surface to make it sharp

точить, оттачивать
  grind your teeth
to rub your teeth together, making an unpleasant sound

скрежетать зубами

Фразовые глаголы grind sb down

GRIND noun

[ no plural ]
 informal uk/ɡraɪnd/ us
work or effort that is boring and unpleasant and makes you tired because it does not change

изнурительная, однообразная работа
the daily grind