ostension
/ɒˈstɛnʃn/noun
1The action of showing, exhibiting, or making manifest; exhibition, display, manifestation; an instance of this. Now rare.
2 Philosophy = ostensive definition.
3 Christian Church. The showing of the consecrated elements to the congregation at the Eucharist; (also) a similar display of some other object of veneration. Now rare ( historical ).
Origin
Late 15th century; earliest use found in William Caxton (1415x24–1492), printer, merchant, and diplomat. From Middle French, French ostension action of showing and its etymon classical Latin ostensiōn-, ostensiō (2nd cent. a.d.; in post-classical Latin also as ostentio, from late 2nd or early 3rd cent.) from ostens-, past participial stem of ostendere + -iō.