illusion
UK[ɪˈluːʒn]US[ɪˈluːʒn]
n
A false idea or belief, especially about somebody or about a situation.
n
Something that appears to exist or to be a particular thing but in reality does not.
Morpheme Breakdown
il
lus
ion
il
in, into, on, upon
lus
ion
Etymology
The word 'illusion' entered English in the 14th century via Old French from the Latin 'illusio', meaning 'a mocking, jesting, irony'. This Latin noun derives from the past participle stem 'illus-' of the verb 'illudere', which means 'to mock at, to play with'. 'Illudere' itself is a compound of the prefix 'in-' (here meaning 'upon, against') and 'ludere' (to play). The core semantic journey is from the literal sense of 'playing games with someone' or 'mocking', to the more abstract concept of 'deceiving the senses or mind', which is the modern meaning of a false perception or belief.
Analysis
Structure: il + lus + ion
il: Latin origin, a variant of the prefix 'in-' meaning 'in, into, on, upon'.
lus: Latin origin, from the root of the verb 'ludere' (to play, mock, deceive).
ion: Latin origin, a suffix forming nouns of action or condition.
Examples
He was under the illusion that he could never be deceived.
The calm surface of the water created an illusion of depth.
The magician's act was a masterpiece of visual illusion.