As a noun, an addict is someone who cannot easily stop using a substance or doing an activity, even when it causes problems. As a verb (usually 'be addicted to'), it means to cause someone to depend on something strongly.
From Latin 'addictus', meaning 'assigned, devoted, or bound to', from 'addicere' (to give over, surrender). It originally described someone legally handed over to a creditor as a kind of slave.
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