It means 'before trees' and specifically refers to a time immediately after the last ice age in Britain, from about 9600BCE until about 8800BCE.
Preboreal
Fact of the Day
Had you stolen an item over 14d in Halifax in 1600, you would be sentenced to die by gibbet
Quote of the Day
"Men make their own history, but they do not make it as they please.
"
~ Karl Marx
On This Day
1586 American colonists arrived in Plymouth with large quantities of tobacco. Smoking caught on quickly, though it was also used in tea.
1694 The Bank of England was founded by an act of parliament as a way to finance government debt by private subscription.
1943 The concentrated Allied bombing of Hamburg led to a three hour firestorm that killed approx 30,000 civilians.