E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
(the month) is not derived from Maia, the mother of Mercury, as the word existed long before either Mercury or Maia had been introduced. It is the Latin Maiusi.e. Magius, from the root mag, same as the Sanscrit mah, to grow; and means the growing or shooting month.
May unlucky for weddings. This is a Roman superstition. Ovid says, The common people profess it is unlucky to marry in the month of May. In this month were held the festivals of Bona Dea (the goddess of chastity), and the feasts of the dead called Lemuralia.
Nec viduæ tædis edem, nec virgnis apta
Tempa; quæ nupsit, non diuturna fuit;
Hæc quoque de causa, si te proverbia tangunt,
Mente malum Maio nubre vulgus ait.
Ovid: Fasti, v. 496, etc.
Here we go gathering nuts of May. (See NUTS OF MAY.)