buckling

Short definition from Wiktionary

Noun

1. 1
   The act of fastening a buckle.
2. 2
   A folding into hills and valleys.
3. 3
   The action of giving in (slightly) to pressure or stress by developing a bulge, bending or kinking (with the eventual risk of collapsing).
4. 4
   A young male domestic goat of between one and two years.
5. 5
   Smoked herring.

Adjective

1. 1
   Wavy; curly, as hair.

Verb

1. 1
   present participle and gerund of buckle