noun
layout object
Technical computing term for an object used in layout processes, such as in desktop publishing or document formatting.
このソフトでは、割付け対象体をドラッグして配置できます。
In this software, you can drag and place layout objects.
Compound of 割付け (わりつけ, 'layout, assignment') + 対象体 (たいしょうたい, 'target object'). The exact derivation is uncertain; it appears to be a technical term formed within computing contexts.