Indicates an immediate need for something when other options have failed or are unavailable. The band was casting around for a new drummer hours before the concert.
Pro Tip 2/3
Wide Range
Suggests considering a variety of options or sources, not being limited to the obvious ones. After the storm, they cast around for any usable materials to repair their house.
Pro Tip 3/3
Unexpected Situations
Often used when circumstances change and require a new solution or plan. The unexpected guests had them casting around for extra chairs and place settings.