0
more casual, most casual
They are in a casual relationship, it's not serious.
I decided to dress casual on Friday.
The opposite of casual is formal.
Their behaviors are so similar and their differences so vanishingly negligible
that to any casual observer, they appear virtually identical. Controlled tests
in the laboratory environment support this widespread impression.
we had a casual day in the office today.
yesterday, we had a free casual day at school.