word of the day: incunabula

From OED:

L. incunabula(neut. pl.) swaddling-clothes, hence cradle, and fig. childhood, beginning, origin, f. cunæ cradle.

1. The earliest stages or first traces in the development of anything.

2. (With sing. incunabulum): Books produced in the infancy of the art of printing; spec. those printed before 1500.

3. Ornith. The breeding-places of a species of bird. Hence incunabular a., of or pertaining to early printed books.

Earliest usage was in the first sense, by Thomas de Quincey in 1824: "Here they fancy that they can detect the incunabula of the revolutionary spirit."