1 Noun. The clenching of the Gluteus Maximus.
2 Adj. A word used to describe a tense, awkward or painful moment. This word was used by Bear Grylls whilst making a dangerous descent down a rock cliff in Man Vs Wild.
Buttock-clenching is a phrase used by British people.
1 Buttock-clenching helps strengthen the Gluteus Maximus.
2 That fall looked buttock-clenchingly painful.
Buttocks décolletage is a fashion in which the person deliberately wears her jeans or other clothing short or low enough to expose the upper part of the cheeks and crack.
The dress I tried on allowed too much buttocks décolletage, even for the Gulf Coast beach hangouts.