To subsume something is to treat it as part of a bigger group or category instead of keeping it separate. It is an academic, formal verb — you meet it in essays, reports and organisational talk, almost never in chat. Two common shapes. First, in thinking and classifying: 'we can subsume these three problems under one heading' — you decide the small cases belong inside the big class. Second, in organisations: when a small department is subsumed into a larger one, it stops existing on its own; its work continues but its separate name and identity are gone. The passive is very common — things are usually 'subsumed into' or 'subsumed under' something. There is often a slight feeling of loss in it: the smaller thing does not just join, it disappears into the larger thing. Writers use that quietly when they want to hint that something particular got swallowed by something general.

歸入、納入（把小的併進大的類別或組織裡）；被併吞後失去獨立性