This is the 16229th most frequent Turkish word.
yalancı
Liar.
The word 'yalancı' is used here as a noun to mean 'liar'.
O, yalancı olduğu için kimse ona güvenmiyor.
Because he is a liar, no one trusts him.
Here, 'yalancı' describes 'smile' and means 'fake' or 'not genuine' as an adjective.
Yağmur korka korka yalancı bir gülümsemeyle selam verdi.
Yağmur greeted with a fake smile hesitantly.
In this example, 'yalancı' modifies 'shepherd' and refers to someone lying in a metaphorical or storytelling context.