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 THALLUS. : a plant or plantlike body (as of an alga, fungus, or moss) that lacks differentiation into distinct members (as stem, leaves, and roots) and does not grow from an apical point. a plant body that lacks differentiation into distinct parts (as stem, leaves, and roots), does not grow from an apical point, and is characteristic of organisms formerly classified as thallophytes. ADVERTISEMENT.