Definition of "pitchy"

Mancunium, Manceaster, what we now call Manchester, spins no cotton […] The Creek of the Mersey gurgles, twice in the four-and-twenty hours, with eddying brine, clangorous with sea-fowl; and is a Lither-Pool, a lazy or sullen Pool, no monstrous pitchy City, and Seahaven of the world!

1843 April, Thomas Carlyle, “ch. 5, Twelfth Century”, in Past and Present, American edition, Boston, Mass.: Charles C[offin] Little and James Brown, published 1843, book II (The Ancient Monk)

In front of me the road became pitchy black as though it was tarred, and I saw a contorted shape lying across the pathway.

1898, H.G. Wells, The War of the Worlds, London: William Heinemann, page 280

To make it worse, something went wrong wit the Glow-worm's lighting system, and the room was in pitchy darkness.

1961, Roald Dahl, James and the Giant Peach, Knopf, page 44