What is the meaning of Philopena?

A game in which a person, on finding a double-kernelled almond or nut, may offer the second kernel to another person and demand a playful forfeit from that person to be paid on their next meeting. The forfeit may simply be to exchange the greeting "Good-day, Philopena" or it may be more elaborate. Philopenas were often played as a form of flirtation.

The occasion on which a philopena is forfeited; the forfeit paid.

A nut or almond with a double kernel, as used to set a philopena.

Source: wiktionary.org