illusion
/ɪˈljuːʒən/noun
1- a false idea or belief错误的观念; 错误的理解：
he had no illusions about the trouble she was in.
他深知她的困境。
1.1
- a deceptive appearance or impression假象：
the illusion of family togetherness
家庭和睦的假象
mass noun the tension between illusion and reality.假象与现实之间的紧张关系。
1.2
- a thing which is or is likely to be wrongly perceived or interpreted by the senses幻觉, 错觉：
Zollner's illusion makes parallel lines seem to diverge by placing them on a zigzag-striped background.
将平行线置于锯齿形条纹的背景上, 策尔纳幻觉会让这些平行线看似形成分岔。
短语
be under the illusion that
- believe mistakenly that错误地认为：
the world is under the illusion that the original painting still hangs in the Winter Palace.
全世界的人都错误地认为原画还挂在冬宫内。
be under no illusion（或illusions）
- be fully aware of the true state of affairs对真实事态一清二楚。
派生词
illusional
adjective词源
Middle English （in the sense 'deceiving, deception'）： via Old French from Latin illusio（n-）, from illudere 'to mock', from in- 'against'+ ludere 'play'.