This word (tsebi) probably comes from the Turkish word "cep" [djep] which in turn comes from Arabic! Fun stuff!
Yes, Greek has quite a number of loanwords from Turkish, mostly with the -ι ending.
Jayb = جيب
Τσέπη = tsepi = sounds like= جيبي = my pocket
It passed to Greek from Turkish during the Ottoman period
When will there be a course of Arabic in Duolingo? ;-)
There is one now :)
is "it is a pocket" definitely incorrect?
Yes. "A" and " the" are not the same.