DictionarycasualRelaxed and informal
adjective / noun

casual

KAZH-oo-uhl/ˈkæʒuəl/

Without formal arrangement or sustained commitment.

She takes a casual break, lounging comfortably in the armchair.

A young woman in a loose T-shirt, jeans, and sneakers lounges comfortably sideways in an armchair, showing relaxed posture and informal dress.
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

Gentleman's Gazette7:44
You can also wear them with shorts and polo shirts. Always bear in mind it’s a casual shoe
Driving Mocs - Why Handmade Leather Mocassins Are Perfect Casual Spring Summer Shoes & How To Wear

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.