Occupied, busy, or kept busy; engaged in activity.
From em- (meaning 'to put into') combined with busy. This archaic word essentially meant 'to make busy' and existed as both verb and adjective forms in Middle English but fell out of use by the 17th century.
Medieval English had lots of em- prefix verbs that didn't survive, like embusy, embitter, and emplume, showing that English speakers gradually preferred other ways to express 'making something busy' rather than this prefix system.
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