Loch Lao is the original Irish name of Belfast Lough. It signifies 'sea-inlet of the calf'. A form of this was recorded as Logia by the Greek geographer Claudius Ptolemy on his map of Ireland, c. AD 150. However, this is a female name, whilst Ir. lao is a masculine noun.
This street name is unusual in being borrowed directly from a water feature without the addition of any word meaning 'street' or similar.