The Collaborative International Dictionary
Ostension
Ostension \Os*ten"sion\, n. [L. ostensio a showing: cf. F. ostension. See Ostend.] (Eccl.) The showing of the sacrament on the altar in order that it may receive the adoration of the communicants.
Wiktionary
ostension
n. (context philosophy English) The act of ostending, of presenting an ostensive definition.