IPA: /dɪˈsɛptɪvli/
KK: /dɪˈsɛptɪvli/
In a way that is misleading or intended to trick someone.
The advertisement was deceptively simple, hiding the product's flaws.
Deceptively → It is formed from "decept" (from Latin "deceptus", meaning misled or deceived) and "-ively" (meaning in a manner). The word "deceptively" means in a manner that misleads or causes someone to believe something that is not true.
Think of being misled ('decept') and doing so 'in a manner' ('-ively') — that's why deceptively means to mislead someone in a certain way.