This is the 4953rd most frequent Turkish word.
gelenlerin
"Of those who come" or "of the ones who arrive."
'Gelenlerin' refers to 'those who came', functioning as a possessive noun describing the possessors of the expressions.
Gelenlerin yüz ifadeleri çok heyecan vericiydi.
The expressions of those who came were very exciting.
'Gelenlerin' indicates 'those who came', specifying the subjects of the fun.
Bu etkinlikte, gelenlerin hepsi çok eğlendi.
In this event, all of those who came had a lot of fun.
'Gelenlerin' means 'of those who came', representing the possessors of the names needing listing.