psyllium
Concise Oxford English Dictionary © 2008 Oxford University Press:
psyllium /ˈsɪlɪəm/
▶noun a plantain whose seeds are used as a laxative and in the treatment of obesity. [Plantago psafra.]
– origin C16: via L. from Gk psullion, from psulla ‘flea’ (because the seeds resemble fleas).
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