[ground.sel] n [ME groundeswele, fr. OE grundeswelge, fr. grund ground + swelgan to swallow--more at swallow] (bef. 12c): any of various senecios (as the nearly cosmopolitan weed Senecio vulgaris)
[2]groundsel n [ME ground sille, fr. ground + sille sill] (15c): a foundation timber