Eyup Mr Tree,

A bit of googling came up with:
'an area of land which has been cultivated for a while and then allowed to revert to heath'
Or:
'from the Gaelic word breac, meaning speckled'
Or:
'a feminine noun meaning slope, from the Scandanavian'

But more of direct relevance, from http://www.lancslinks.org.uk/linkscontent/mycommunity/localcommunity/blackpool/
Is:
'The name 'war' is thought to derive from the Old English word 'waer' meaning a settlement by a weir, with the word 'breck' deriving from 19th century slang for break, meaning an area of land that has been broken up for cultivation. Warbreck Hill in north Blackpool is probably the highest point on the Fylde, it is believed to have been a beacon hill in ancient times, there is talk of it being used by the Druids; is it so inconceivable that the Romans also would have utilised its commanding position as a lookout post? Who knows what evidence may have been destroyed when in the 1920s the water board built a reservoir and the massive water tower which now occupies the crest of the hill, and why is the hill's real name "Beryl Hill"? This suggests a link with celtic gods to me. Also worth mentioning is the fact that this hill was used along with Beacon Fell for triangulation purposes during the first ordnance survey of Lancashire; this is because from the hills Warbreck is easily seen, just as it was in Roman times'

Which I suspect you may have seen already, so not all that much help really, soz.

But it's nice to see there is at least a small bit of evidence for prehistoric Blackpool. I've noticed it's a bit sparse round there, which always seems a bit unlikely, given the good farming land. Mebbe it wasn't so good back in the dim and distant.