source: By Original by Edward H. Adelson, this file by Gustavb - File created by Adrian Pingstone, based on the original created by Edward H. Adelson, Copyrighted free use

a thing that is or is likely to be wrongly perceived or interpreted by the senses:

«…という/…についての» 幻想, 錯覚, 勘違い; U錯覚すること «that節/about» (!比較的ありがちな思い違い; delusionはありそうにないことを強く信じ込むこと)

e.g. the illusion makes parallel lines seem to diverge by placing them on a zigzag-striped background.

a deceptive appearance or impression:

幻覚, 幻影, まぼろし

e.g. the illusion of family togetherness

e.g. the tension between illusion and reality.

a false idea or belief:

e.g. he had no illusions about the trouble she was in.

believe mistakenly that:

e.g. the world is under the illusion that the original painting still hangs in the Winter Palace.

be under no illusion (also be under no illusions)

be fully aware of the true state of affairs.

illusional |-ZHənl| adjective

illusionary |iˈlo͞oZHəˌnerē| adjective

Middle English (in the sense ‘deceiving, deception’): via Old French from Latin illusio(n-), from illudere ‘to mock’, from in- ‘against’ + ludere ‘play’.