Wages, reward, or mercy
A rare phonetic spelling of the Spanish name Mercedes. It ultimately derives from the Latin word 'merces', referring to the Virgin Mary as 'Maria de las Mercedes' (Mary of Mercies).
Less common today
Mercadies isn't in the latest US Top 1000. It last peaked at #7,471 in 1993.
US births per 5-year period, 1990βpresent (SSA data).