casual

US /ˈkæʒ.uː.əl/
UK /ˈkæʒ.uː.əl/
"casual" picture
1.

relaxed and unconcerned

:
He adopted a casual attitude towards his studies.
She gave a casual shrug, indicating her indifference.
2.

without formality of style or manner

:
They had a casual conversation over coffee.
The dress code for the event is casual.
3.

happening by chance; accidental

:
Their meeting was purely casual.
He made a casual remark that turned out to be very important.