buluşmak means to meet..its the cooperative form of the verb bulmak..to find
bulmak..to find
bulUŞmak to find each other..ie to meet.
the addition of UŞ turns the verb into one of interaction or cooperation.
like görmek ..to see..and görÜŞmek to see each other
anlamak to understand..anlAŞmak to...