The leaves and tender parts of the Indian hemp plant (which are intoxicating), which are dried for either chewing or smoking.
1855, Sir Richard Burton, Personal Narrative of a Pilgrimage to Al-Madinah and Meccah, Dover 1964, p. 44:
Coyly at first, but less guardedly as we grew bolder, we smoked the forbidden weed "Hashísh," conversing lengthily the while about that world of which I had seen so much.