in a way that shows you are calm and relaxed

without much care or thought; without paying attention to detail

Many people casually dismiss these claims.

She glanced casually out of the window.

showing that you do not want people to know that something is important to you

‘What did he say about me?’ she asked as casually as she could.

if somebody is dressed casually, they are not dressed formally

dressed casually in jeans and T-shirt

I casually dated a few people during that time but had no serious relationship.

(British English)casually employed workers

LEARNit Dictionary