This is the 12359th most frequent Turkish word.
hayli
"Hayli" means "quite a lot" or "considerably" in English.
Here, 'hayli' is used to indicate a significant amount of time.
Bu çalışma, hayli zaman aldı.
This work took quite a lot of time.
In this sentence, 'hayli' denotes an emphatic description of how nice the dress looks.
Elbise hayli güzel görünüyor.
The dress looks rather beautiful.
'Hayli' here emphasizes the necessity of substantial attention or thought.