derrière

[ der-ee-air; French de-ryer ]

/ ˌdɛr iˈɛər; French dɛˈryɛr /

the buttocks; rump.

Origin of derrière

1765–75; < French (preposition, noun); Old French deriere < Vulgar Latin *dē retrō, for Latin retrō towards the rear, backwards; cf. arrear

derrick, derrida, derring-do, derringer, derris, derrière, derro, derry, dertrum, derv, dervish

She received so much attention her derriere was even given its own Facebook page.

Pippa and Alex - Parents Unconvinced |Tom Sykes |July 19, 2012 |DAILY BEAST
His leather jackets and vests were constructed with peplums that swirled and blossomed just above the derriere.

Paris Fall 2012 Fashion Week: Haider Ackermann, Lanvin, and Comme des Garçons |Robin Givhan |March 4, 2012 |DAILY BEAST
Lest her little monster fans worry, as she stepped on stage, her derriere did not appear to have been impaled.

Lady Gaga, New Designers Lauded at 2011 CFDA Awards |Robin Givhan |June 7, 2011 |DAILY BEAST
Eventually, Williams joined him on stage and playfully smacked his derriere with a tennis racket in the shape of a heart.

13 Award Show Hosts Dos and Don'ts |Sujay Kumar |November 29, 2010 |DAILY BEAST

derrière

/ (ˌdɛrɪˈɛə, French dɛrjɛr) /

euphemistic the buttocks

C18: literally: behind (prep), from Old French deriere, from Latin dē retrō from the back