V. S. Apte, The Practical Sanskrit–English Dictionary. Look up any word of the Gita in Devanagari, IAST or Harvard-Kyoto, or browse the headwords letter by letter.
-रसः the juice of the wild date (Marâthîताडी); also खर्जूरीरसः. denotes that the rest of the word under consideration is to be suppliedजः a kind of sugar.