The name Birkenhead probably means "headland overgrown with birch", from the Old English bircen meaning birch tree, of which many once grew on the headland which jutted into the river at Woodside. The name is not derived from the Birket, a stream which enters the Mersey between Birkenhead and Seacombe. The Birket is a later name which was introduced by Ordnance Survey.
Given this paragraph about the town of Birkenhead, what the does the name Birkenhead probably mean?
It probably means "headland overgrown with birch".