the.com/sandbank

means A ridge or mound of sand built up underwater or at a shoreline by currents and tides, often shallow enough to strand boats or break the surface at low tide.

from A plain compound of 'sand' and 'bank,' where 'bank' carries its old sense of a raised shelf, ridge, or edge — the same sense surviving in 'riverbank.' Both words trace back through Old English, with 'bank' likely related to Germanic words for a raised shelf or ridge of ground. No hidden story here — it's a literal name for a literal thing, which is part of why it's lasted so plainly intact for centuries.