buckle down
Intermediate (B1)informal
To stop messing around and start doing your work properly.
"You need to buckle down and study if you want to pass these exams."
Hear it in context

What to Do When You’re Told There’s Nothing Left to Try | David Fajgenbaum, Kiah Williams | TED
TED · 2:27
work really hard, buckle down in school,

Marty Lobdell - Study Less Study Smart
Pierce College District WA · 3:03
She decided she really needed to buckle down,

YES, it's possible - Daily Routine at C1 (Advanced) Level of English!
English with Lucy · 8:21
buckle down and get on with my work meticulously

Bezos Just Showed You Everything Wrong With This Country
The Chris Cuomo Project · 23:21
Now is the time to knuckle up and buckle down.

Barbaric The foul mouth Jedi / The Honorable DJ Metal Monkey 🐒 Radio show
DJ Metal Monkey Radio Show · 53:02
when it's time to like to buckle down and go record.