WordNet sense 1 (serving to support or corroborate):

corroborative, corroboratory, confirmative, confirmatory, confirming, substantiating, substantiative, validating, validatory, verificatory, verifying

WordNet sense 2 (being of second rank or importance or value; not direct or immediate):

secondary

WordNet sense 3 (being everywhere equidistant and not intersecting):

parallel

WordNet sense 4 (descended from a common ancestor but through different lines):

indirect