adjective / noun
casual
KAZH-oo-uhl/ˈkæʒuəl/
Without formal arrangement or sustained commitment.
She takes a casual break, lounging comfortably in the armchair.

Etymology
Latin casus connected “a falling” with an event—something that “befalls” someone. Casual originally meant “by chance,” developing toward lack of regularity or planning and the relaxed informality associated with casual clothes.
In context
You can also wear them with shorts and polo shirts. Always bear in mind it’s a casual shoe
More examples
- She takes casual work during the summer.
- Their casual acquaintance grows into a close friendship.
- A casual encounter at the station changes his plans.
Forms
casual · casuals
Similar words
- informal
- Specifically lacks formal rules or ceremony.
- occasional
- Specifically happens at intervals rather than regularly.