Plural of estuary; the mouths of rivers where they widen and meet the ocean, with tides and salt water reaching inland.
From Latin 'aestuarium' (inlet), from 'aestus' (surge, tide). The Romans named these areas after their most obvious feature: the tidal surge.
Estuaries are sometimes called 'nurseries of the sea' because countless fish and shellfish are born there, and despite covering only 0.8% of ocean area, they support 80% of commercially fished species.
Complete word intelligence in one call. Free tier — 50 lookups/day.