Definition of pendentive in English:
 pendentive
noun pɛnˈdɛntɪvpɛnˈdɛn(t)ɪv
Architecture A curved triangle of vaulting formed by the intersection of a dome with its supporting arches.
 Example sentencesExamples
-  Each storey is articulated by a balcony, projecting on a system of stalactite pendentives - this feature appearing for the first time in India and no doubt imported from classical Islamic construction.
 -  Two structural devices that are the hallmark of Byzantine engineering made this feat possible: pendentives and squinches.
 -  His most important commission was for the apse and the pendentives beneath the cupola in; the dome was commissioned from his great rival, the Baroque painter.
 -  The spaces are called spandrels - or pendentives, but the more general architectural term is spandrels.
 -  Convex looking glasses in each pendentive both explode and compress the space.
 
Origin
  
Early 18th century: from the French adjective pendentif, -ive, from Latin pendent- 'hanging down', from the verb pendere.
   Definition of pendentive in US English:
 pendentive
nounpɛnˈdɛn(t)ɪvpenˈden(t)iv
Architecture A curved triangle of vaulting formed by the intersection of a dome with its supporting arches.
 Example sentencesExamples
-  Convex looking glasses in each pendentive both explode and compress the space.
 -  The spaces are called spandrels - or pendentives, but the more general architectural term is spandrels.
 -  Two structural devices that are the hallmark of Byzantine engineering made this feat possible: pendentives and squinches.
 -  Each storey is articulated by a balcony, projecting on a system of stalactite pendentives - this feature appearing for the first time in India and no doubt imported from classical Islamic construction.
 -  His most important commission was for the apse and the pendentives beneath the cupola in; the dome was commissioned from his great rival, the Baroque painter.
 
Origin
  
Early 18th century: from the French adjective pendentif, -ive, from Latin pendent- ‘hanging down’, from the verb pendere.