Earthlore

He even wondered what would happen to him when the sages of Tsath considered him drained dry of fresh facts; and in self-defence began to be more gradual in his talks on earth-lore, conveying whenever he could the impression of vast knowledge held in reserve.

Luca pulled thoughtfully at his lower lip. “You shouldn't have been able to hide from us before. We're aware of the whole world.” “My people still have the earthlore your kind — both of you — have forgotten.

Here Rhion read and studied through the rainy days of the marshlands winter and sometimes throughout the night: herb-lore and earth-lore and the deep magics of the moon and tides; the legends of the old realm of Sligo, going back two thousand years; […]

I will say that my comrade, the Doctor, did much to make it so, with his gentle fun, and his wide knowledge of earth-lore.