Earlier this year, I wrote about a post about epitaphs. At that time, I made the decision to not combine them with elegies.
An elegy is a song of sorrow or mourning--often for someone who has died. However, poets being an especially creative and contrary group have also written elegies for the ends of things, whether a life, a love affair, a great era, a football season, etc.
While there are such things as elegiac couplets and elegiac stanzas, form does not rule an elegy; content is king (or queen) when writing elegies.
Here are some examples:
"Elegy in Present Tense," by Nancy Krygowski
"Elegy Written in a Country Courtyard," by Thomas Gray
Here's some more on elegies: