buckling up

Verb

buckle up (third-person singular simple present buckles up, present participle buckling up, simple past and past participle buckled up)

1. (transitive) To fasten with a buckle.
   • It was eight o'clock to-morrow evening when I buckled up my travelling writing-desk in its leather case, paid my Bill, and got on my warm coats and wrappers.1855, Charles Dickens, “The Holly-tree. Third Branch—The Bill”, in Christmas Stories […] (The Works of Charles Dickens; XV), de luxe edition, London: Chapman and Hall, published 1881, →OCLC, page 63
2. (idiomatic, intransitive) To fasten one's seat belt or safety belt.
   • Buckle up every time you drive somewhere in a car, and make sure your passengers buckle up, too.

   Synonyms:

   belt up

3. (broadly, idiomatic, imperative, intransitive, usually) To get ready, to prepare oneself.
   • So buckle up for what's coming, readers!2019 February 27, Robert Kirkman, Outcast By Kirkman & Azaceta #39, Image Comics