Mavis is a feminine given name, derived from a name for the common Old World song thrush. Its first modern usage was in Marie Corelli's 1895 novel The Sorrows of Satan, which featured a character named Mavis Clare (whose name was said to be "rather odd but suitable", as "she sings quite as sweetly as any thrush"). The name was long obsolete by the 19th century, but known from its poetic use, as in Robert Burns's 1794 poem Ca' the Yowes ("Hark the mavis evening sang/Sounding Clouden's woods amang"); and in the popular love song "Mary of Argyle" (c.
https://en.wikipedia.org/wiki/Mavis