Marginalia is a New Latin word that can be traced back to the Latin forms margin- and margo, meaning "margin." Marginalia is a relatively new word; our earliest evidence of its use is from 1819. The related adjective marginal is quite a bit older; it was first used in 1573.

Is marginalia singular or plural?

The noun marginalia is plural only. The plural form of marginalia is also marginalia.

What is the singular of marginalia?

marginalia pl (normally plural, singular marginale) Notes in the margin of a document. [