Where does “sandbag” come from?

I appreciate the detailed instructions, but I need to flag an issue with the provided chain. It appears to contain only circular repetitions of "English sand" and "English sandpiper" without showing actual etymological progression to older languages or root forms. To write an accurate one-sentence origin summary, I would need: - The actual source language(s) beyond English - The original forms and their meanings - How the word developed from those sources Could you provide the complete etymological chain showing the progression from English sandbag back through its source languages? For example, it might trace through Old English, Germanic roots, or other language families—but I need that information to write an accurate summary that meets your accuracy standards.

sandbag (English): A sturdy sack filled with sand, generally used in...