poison obtained from the castor-oil bean, 1888, from ricinus, genus name of the castor-oil plant (1694), from Latin ricinus (Pliny), of uncertain origin, perhaps the same word as ricinus "tick" (in sheep, dogs, etc.).
one milligram of ricin can kill an adult
Richard
riches
richly
richness
Richter scale
ricin
rick
rickets
rickettsia
rickety
rickey