Choose the perfect synonym or antonym for the word

Casual

/ˈkæʒuəl/

Something that is done or worn in a relaxed and not very formal way.

Synonyms:

The director's voice was casual.

'They will not let you be more than a Casual there.

You needn't meet her except in a casual way.

Derived from the Late Latin casualis meaning by chance, combining casus (a fall, case) with the suffix -alis.

15 mentions per 1 million words

Moderate

Hint: Frequency according to COCA