In the CSS Containment Module L3 we define container-type, and container-name properties, along with a container shorthand.

I personally think "container" is the clearest term we have for this feature (and twitter seems to agree, but there is some potential for confusion. We already have a (related but different) contain property, and many other variations pm "container" terminology in CSS specifications.

Other names that have been suggested:

• query (clear association, but the verb doesn't entirely make sense when applied to the containing element)
• context
• component
• module
• structure
• viewbox
• enclosure
• compartment

Unfortunately, many of these alternative also have existing meaning that could cause confusion.

(Depending on the language we choose, @container may also need to be updated.)