cushy is borrowed from Hindi ख़ुश ḵẖuś "pleasant", which is borrowed from Persian خوش khush "good, excellent". According to Platts, the word is cognate with Avestan usta "fortunate" (from uś + śtā) and Sanskrit ud + sthā. Maybe the meaning in Avestan and Sanskrit is something like "outstanding"?
Sometimes Platts's etymologies seem farfetched. Where did the initial consonant come from?
Anyway, Sanskrit ud "up, upwards; upon, on; over, above" is from Proto-Indo-European *ud- "up, out". This became Old Church Slavonic vъz- and Russian вы "out" in the word выигрыш (vyigryš) "gain, winnings". This word was borrowed into Yiddish and then into English as vigorish, defined by the OED as "The percentage deducted by the organizers of a game from the winnings of a gambler. Also, the rate of interest upon a usurious loan."
Also see Orthanc and hysteresis.