Some common synonyms of relevant are applicable, apposite, apropos, germane, material, and pertinent. While all these words mean "relating to or bearing upon the matter in hand," relevant implies a traceable, significant, logical connection.

// found material relevant to her case

Although the words pertinent and relevant have much in common, pertinent stresses a clear and decisive relevance.

// a pertinent observation

The synonyms apropos and relevant are sometimes interchangeable, but apropos suggests being both relevant and opportune.

// the quip was apropos