Precocious OED

Precocious
1 Of a plant: Flowering or fruiting early; spec. bearing blossom before the leaves; also said of the blossoms or fruit.
2 fig. Of persons: Prematurely developed in some faculty or proclivity.

From the Latin praecox (premature?). Which when it made it to the French became praecoquere and means to pre-cook, to boil beforehand.

Walking home from the bar on Saturday, we were discussing the 12 year old stripper. The word precocious was used. I found that I didn't know exactly what was meant by that. I am quite surprised to find the definition to be so rigid, that it hasn't become sloppy english to mean anything else.
It took me a bit to find the antonym, serotious.

Serotine
a. Late in occurance or development; chiefly of plants late flowering.
sb. A late flowering plant or species.

It's also the name of a bat. One that is seen late in the evening. It's interesting that the one word is a commonly used and widely understood one, while even the definition of it's opposite points exclusively towards a purely zoological origin and usage. Every comprehends a precocious child. No one understands the serotious man. Which I like to think I am.