This is the 15363rd most frequent Turkish word.
süresiz
"Indefinite" or "without a time limit."
Here, 'süresiz' is used to describe the membership period, meaning 'indefinitely', implying no time limit.
Bu üyelik süresiz olarak geçerlidir.
This membership is valid indefinitely.
In this sentence, 'süresiz' describes the borrowing period, again meaning 'indefinitely', with no deadline for return.
Bazı kitaplar kütüphanede süresiz olarak ödünç alınabilir.
Certain books can be borrowed indefinitely from the library.
'Süresiz' in this example signifies the duration of the vacation, indicating 'not limited by time' or 'without an end date'.