This is the 17029th most frequent Turkish word.
çağındayken
"Çağındayken" means "while at the age of" or "during the time/era of."
In this sentence, 'çağındayken' specifies the particular age or period of Ahmet during which he studied, indicating the timeframe of university age.
Ahmet üniversite çağındayken yurtdışında eğitim aldı.
Ahmet studied abroad while he was at university age.
Here, 'çağındayken' denotes Maria's childhood period, pointing out the timeframe during which she enjoyed painting.
Maria çocukluk çağındayken resim yapmayı çok severdi.
Maria loved painting very much while she was in childhood age.
In this case, 'çağındayken' describes the period of Ali's youth when he started engaging in sports.