Hydrogenation Definition: Hydrogenation is a reduction reaction which results in an addition of hydrogen (usually as H2). If an organic compound is hydrogenated, it becomes more 'saturated'. Hydrogenation has many applications, but most people are familiar with the reaction as the one used to make liquid oils into semi-solid and solid fats.
thistle in American English (ËÎ¸ÉªsÉl ; t hisËÉl) noun. any of various plants (as genera Onopordum, Cirsium, and Cnicus) of the composite family, with prickly leaves and heads of white, purple, pink, or yellow flowers; esp., the Scotch thistle (O. acanthium) with white down and lavender flowers.
Medical Definition of milk thistle. 1  1: a tall thistle (Silybum marianum) that is the source of silymarin, has large clasping white-blotched leaves and large purple flower heads with bristly receptacles, and is native to southern Europe but has been widely introduced elsewhere including the United States.