/ɪ'lu:ʒn; ɪ`luʒən/
n
1 (a) [C] false idea, belief or impression; delusion 错误的观念; 幻觉; 错觉
*I have no illusions about my ability, ie I know that I am not very able. 我对自己的能力如何颇有自知之明（我知道自己的能力不很强）.
* We're left with few illusions about ourally. 我们的处境已不容我们对盟友再存多少幻想了.
(b)[U] state of mind in which one is deceived in this way 幻觉; 错觉
*You think that, do you? Pure illusion! 你是那么想的吗? 纯粹是错觉!
2 [C] thing that a person wrongly believes to exist; false perception 幻想中的事物; 错觉
*an optical illusion 光幻视
* In the hot sun the surface of the road seems wet, but that is only an illusion. 路面在烈日之下像是湿的, 然而这仅仅是错觉.
3 (idm 习语) be under an/the illusion (that...) believe wrongly 误信
*I was under the illusion that he was honest until he was caught stealing some money. 他偷钱当场被人抓住, 在此之前我一直误以为他是个老实人.

n[C]
[Date: 1300-1400; Language: French;Origin:Latin illusio, from illudere 'to make fun of', from ludere 'to play']
an idea or opinion that is wrong, especially about yourself
→delusionillusion that
　They suffer from the illusion that they cannot solve their problems.
　She was under no illusion that he loved her.
　It is an illusion that the Arctic is dark in winter.
　She had no illusions about her physical attractions.
　'I hate to shatter your illusions,' he said.
something that seems to be different from the way it really is
illusion of
　He was unlikely to be satisfied with the illusion of power.
give/create an illusion
　The mirrors in the room gave an illusion of greater space.
　Credit creates the illusion that you can own things without paying for them.
→optical illusion