■ adverb
1》 to a lesser extent than appears the case: the idea was ~ simple.
2》 to a greater extent than appears the case: the airy and ~ spacious lounge.
Usage
Deceptively can be used in similar contexts to mean both one thing and also its complete opposite. A ~ simple plan is one that is not simple at all, while a ~ spacious room is in fact more spacious than it appears. But what is a ~ steep gradient ? To avoid confusion, it is often best to reword rather than use ~ .