IPA: /ɪˈluːsəˌrɪli/
KK: /ɪˈluːsəˌrɪli/
In a way that creates a false impression or belief; not real or true.
The magician performed his tricks illusorily, leaving the audience in awe.
Illusorily → It is formed from "illusory" (from Latin "illusorius", meaning deceptive or misleading) and the suffix "-ly" (meaning in a manner of). The word "illusorily" means in a deceptive or misleading manner.
Think of something that is 'deceptive' ('illusory') and remember that 'illusorily' means acting in a deceptive way.