百年不遇 once in a blue moon ; only met with once every hundred years

孤独不遇 beindirestraits ; bedownandcast

怀才不遇 unrecognized for one's talent ; Having unrecognized talent

不遇敌 No Encounters

怀才不遇者 Misunderstood Geniuses

山中访仙不遇 I went into the mountain to visit the immortal

寻隐者不遇 a note left for an absent ecluse

不期而遇 Meet by chance ; Encounters ; run across ; come across

遇人不熟 A Stranger of Mine