The present participle of 'encage'; the act of putting or keeping something in a cage.
From encage + -ing suffix, which forms the present participle and gerund forms of verbs in English.
In modern usage, you're more likely to see 'caging' than 'encaging,' but the -ing form keeps old verbs alive—you can find 'encaging' in older literature describing the trapping of animals or imprisonment!
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