Of the marsh or from the sea
Demere is likely a variant of the French surname De Mare, meaning 'from the pond' or 'of the sea.' It may also be a phonetic variation of the Greek name Demetrius, though it is most commonly used as a rare surname-turned-given-name in the United States.
Less common today
Demere isn't in the latest US Top 1000. It last peaked at #6,980 in 2010.
US births per 5-year period, 1990βpresent (SSA data).