The etymology of this word (and its precise sense) is obscure. See, however, Gdf 10,57b rieble (‘grateron, plante’) and TL 8,375 reble (‘Klebekraut’), for what appears to be the same word without what is possibly a diminutive suffix.
s.
1bot.cleavers (Galium Aparine, a climbing plant which adheres itself to hedges, shrubs or clothes) or burdock (Arctium Lappa, a weedy plant with prickly flower-heads or burs):