Subopup

Subopup is a term used in user interface design to describe a secondary popup element that appears within or in relation to a primary popup. It is typically a nested or subordinate window used to present additional options, details, or actions without requiring the user to close the main popup or navigate away.

Etymology and usage: The term combines sub- meaning under or beneath with popup. It is not a formally standardized term in UI literature, and its meaning can vary between teams and frameworks.

Characteristics: Subpopups are usually triggered by interaction inside the parent popup, such as selecting an item or clicking a control. They can be modal or non-modal and may require additional focus management and ARIA roles for accessibility. Designers use subpopups to reduce navigation steps and preserve context, but they can increase cognitive load and complicate layout and keyboard navigation.

Contexts and examples: Subpopups appear in complex web applications, form wizards, dashboards, and design systems where layered controls exist. Some libraries refer to nested or secondary popups as subpopups or popovers with inner content, although terminology differs across ecosystems.

See also: Related concepts include popups, tooltips, popovers, modals, and nested menus. The term subpopup reflects a general idea of a subordinate popup rather than a single universal standard.