This is the 12072nd most frequent Turkish word.
görmüş
"Seen" (past participle of "see").
In this sentence, 'görmüş' is used as the third-person singular past tense form of the verb 'görmek' (to see), implying an experience or a completed action.
O, bu şehri daha önce görmüş.
He has seen this city before.
In this context, 'görmüş' is part of the compound construction denoting the act of having seen these events as past experiences influencing the present.
Bu olayları görmüş olmak seni daha güçlü yapar.
Having seen these events makes you stronger.
Here, 'görmüş' is employed as part of a compound descriptor 'görmüş geçirmiş,' indicating someone experienced who has seen and gone through many things.