We don’t know exactly from where the name Apulia derives but it is told that it is connected to the chronic lack of water that has always characterized the region. But it has not always been so arid like now. During prehistoric periods there were rivers that surely flowed in Puglia, but almost no trace remains of them except for traces of their passage in the characteristic “lame” (a depression, bed of ancient rivers) that nowadays mark the territory from the ridges of the “Murgia” (so called the Apulian hill on the northen and central part of the region) that run perpendicular to the sea. Today the only surviving river, the Ofanto, in the northern area of Foggia, looks like a miserable river.
One of the well-known lama in Puglia is the most charmign beach in Monopoli: lama Monachile, a suggestive attraction of the town.
Cartography of”lame” in the area Monopoli – Ostuni 
Monopoli, lama Monachile
Actually Apulia is a dry, arid and scanty rainy climate region mostly during the long summer season that in the south begins meteorologically earlier. Despite the significant and evident climatic changes also in Apulia towards a more humid and rainy climate, it’s history that not a drop of water falls from May to the end of August. The absence of water gives the name “a-pluvia”, meaning “without rain” or following some researchers with th Oratian meaning od “arid”, “dry” referring not only to climate but indicating the characteristic red soil:
“Apuglia è detta, ch `l caldo v ‘è tale
che la terra vi perde alcuna volta
la sua vertù e fruttifica male”
(Orazio, Epodi, 3, 16)
The Greek influence
According to others, the name would rather derive from the Greek term “lapudia“, that meant land of the Iapigi, people that conquered the territory in the ninth century led by the king Dauno (from which the name of the Apulian northern area, the Daunia), later transformed by the nearby Samnite people into Apulia.
The modern meaning
Romans identified the same territory as “Apulia et Calabria”, unifying the two peninsular lands of southern Italy, used to refer to central and northern area of present-day Puglia while the southern one (actual Salento) was annexed by Calabria region.
Current name of Puglia is due to the Normans. William of Altavilla in 1042 established the County of Puglia which included all the territory under their dominion. A name that has remained unchanged since then.