noun
composite layout object
A technical term in computing, likely from document formatting or page layout systems, referring to an object that combines multiple layout elements.
このソフトウェアでは、複合割付け対象体を定義して複雑なページレイアウトを実現する。
In this software, you define composite layout objects to achieve complex page layouts.
A compound of 複合 (composite), 割付け (layout, assignment), and 対象体 (target object). The exact derivation is uncertain; it appears to be a technical coinage in computing.