回笼 is a separable verb (离合词) with two distinct meanings. One is literal: 'to steam again' (e.g., reheating leftover steamed buns). The other is financial: 'to withdraw currency from circulation' (e.g., the central bank pulling money out of the economy). When used in the financial sense, it often appears in formal or economic contexts. As a separable verb, elements like 了 or measure words can go between 回 and 笼, e.g., 回了笼.