To work very hard; to put in a lot of effort.
hard at work
Labouring with great effort and diligence; working hard.
put a shift in
To work hard; to make an effort
apply oneself
Synonym of strive: to work hard, to complete an activity with good eff…
elbow grease
Effort or hard work, especially physical work involving repeated motio…
bust ass
To work hard, especially when trying to achieve a goal.
bust one's butt
To work exceptionally hard.