bog rhubarb bogr·hu·barb uncommon noun 1. small Eurasian herb having broad leaves and lilac-pink rayless flowers; found in moist areas Synonymsbutterburbog rhubarbPetasites hybridusPetasites vulgaris Related words Broader terms herb Parts Petasites WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.
