"pertinent to the matter at hand," 1550s, from Middle French relevant "depending upon," originally "helpful," from Medieval Latin relevantem (nominative relevans), from stem of Latin relevare "to lessen, lighten" (see relieve). Not generally used until after 1800.
the scientist corresponds with colleagues in order to learn about matters relevant to her own research
relegate
relegation
relent
relentless
relevance
relevant
releve
reliability
reliable
reliance
reliant