The ancient Greek word for oakum, tow was styppeion or styppe . It is related to the Latin noun stuppa (coarse part of flax, tow) and the verb stuppare (to stop or stuff with tow or oakum, to prevent a flow by blocking a hole). The verb was adopted by many languages (It. stoppare, Fr. etouper, Ger. stopfen) and in English stop.
From the same root: stopper, stopgap, stoppage, stopping, stopple etc.
In modern Greek .
a) stupee: oakum [στουπί]
styppe – stuppa → stoppare → stop
See the blog: English words of no Apperent Greek Origin at: http://ewonago.blogspot.com/