This is the 5854th most frequent Turkish word.
sızan
"Leaking" or "seeping."
Here, 'sızan' is used as an adjective to describe the part of the roof that leaks, derived from the verb 'sızmak' (to leak).
Çatının sızan kısmını tamir ettim.
I repaired the leaking part of the roof.
In this context, 'sızan' is used as part of a descriptive clause indicating the person who intruded into someone's email, the verb 'sızmak' here implies an unauthorized entry.
E-mailine sızan kişiyi tespit ettiler.
They identified the person who hacked into your email.
'Sızan' functions here similarly as an adjective, describing water that has seeped into the soil, highlighting the action performed by the water.