BUCKLE UP or BUCKLE DOWN?

English for Today by Ganiu Abisoye Bamgbose (Dr GAB)

BUCKLE UP or BUCKLE DOWN?

To buckle up is to fasten one’s seat belt in a vehicle or aircraft:
It is advisable to buckle up when driving on highway. ✔️

To buckle down is to tackle a task with determination:
You have to ~buckle up~ to do well in your examination. ✖️
You have to buckle down to do well in your examination. ✔️
GAB