Organized or put in order; prepared or planned in advance.
From Old French 'arranger' meaning 'to put in order,' from 'a-' (toward) and 'range' (row or rank). The word carried the sense of putting things in lines or proper order.
When you arrange something, you're literally putting it in a 'range' or row—that's why 'arrange' and 'range' sound related, and why arrangement suggests things are organized into lines or patterns.
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