Definition of mercurial in English:



  • 1Subject to sudden or unpredictable changes of mood or mind.

    ‘his mercurial temperament’
    • ‘The mercurial singer-songwriter's mood is as unpredictable as Halifax weather and each night's performance lives and dies on which attitude the capricious star brings to the rink.’
    • ‘He grinned briefly in a mercurial change of mood.’
    • ‘Could it be my mercurial temper, causing many rash actions or hurtful, wicked comments?’
    • ‘One of the most talented and versatile Scottish performers, McKidd is mesmerising as Frankie, capturing all the mercurial moods of a man who can switch from sentimentality to aggression at the flick of a switchblade.’
    • ‘During his four years in office, Mr. Chen has proven to be a mercurial and unpredictable leader.’
    • ‘Nor does she depict adolescence as a period of mental instability, characterized by mercurial moods and impulsive, self-gratifying actions.’
    • ‘Jim's mind is mercurial, but I like his company more than anything.’
    • ‘To blow off those dear friends who've put up with your mercurial moods for long is just plain cruel and thoughtless, so start returning those calls and those emails.’
    • ‘He is mercurial, unpredictable and headstrong.’
    • ‘He then embarked upon a legal career which was characterised by often brilliant legal exposition, and mercurial temperament.’
    • ‘At times you feel frustrated with Ellie and her mercurial temperament.’
    • ‘Rhea's temperament was infamously mercurial - one would never know what she was thinking, or when she might strike.’
    • ‘No decision of importance could be made without the chairman, and he was mercurial, often changing his mind once a decision had been made.’
    • ‘In a mercurial change of temper, he grabbed her shoulders and shook her, once, twice.’
    • ‘He had a mercurial temperament and was never one to hold back his views, even in the face of opposition.’
    • ‘Regardless of her mercurial mood, he always managed to stay gentle with her.’
    • ‘Their awkwardness, overextended maturity, mercurial temperaments, and easy companionship were all spot on.’
    • ‘Ms Short is notorious for her outspoken comments and her mercurial temperament.’
    • ‘Okada projected the mercurial shift of moods in Beethoven's Fantasie Op 77 with resonant sonority.’
    • ‘Mrs. Lincoln became known as much for her fashion sense as her mercurial temperament and place in history.’
    volatile, capricious, temperamental, excitable, fickle, changeable, unpredictable, variable, protean, mutable, erratic, quicksilver, inconstant, inconsistent, unstable, unsteady, fluctuating, ever-changing, kaleidoscopic, fluid, wavering, vacillating, moody, flighty, wayward, whimsical, giddy, impulsive
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  • 2Of or containing the element mercury.

    ‘gels containing organic mercurial compounds’
    • ‘Brownish-black may indicate chronic mercurial poisoning caused by the formation of sulfide of mercury in the tissues.’
    • ‘Mercury amalgams are used in dentistry, and mercurial aids such as the thermometer and blood pressure apparatus aid the doctor.’
    • ‘I shuffled off to where he'd pointed, feeling a cold bar of mercurial metal, like in thermometers, stretch from the first bone of my chest, and settling into the pit of my stomach.’
    • ‘Everyone is wise to the mercury dangers in paints, but patients need to know that button batteries, mercurial antiseptics and broken thermometers are sources of mercury.’
    • ‘These mercurial chemicals are never taken lightly.’
    • ‘The mercurial bromide was re-extracted and analyzed by capillary gas chromatography/electron capture detector, using an internal standard for quantification.’
    • ‘Over the years, researchers provided Eli Lilly with numerous articles indicating the hazards of injecting humans with mercurial substances such as thimerosal.’
    • ‘This research is an effort to create an awareness. of the potential hazards of some Chinese patent medicines which contain mercurial ingredients.’
    • ‘The condensation beading on it gave it a mercurial sheen.’
    • ‘And don't forget ‘liquid metal,’ dynamically controlled mercurial globs you can push around on your canvas.’
    • ‘In acute LV failure with pulmonary edema, phlebotomy, rotating tourniquets, and parenteral mercurial diuretics were effective.’
    • ‘To determine the extent to which mercury-sensitive water channels are involved in the control of root water flow, mercurial inhibition of root water flow was also examined using a pressure-flux approach.’
  • 3Of the planet Mercury.

    • ‘Every person, by his own astrological make up will have a Mercurial connection with the transpersonal plants, either by aspect or sign rulership.’
    • ‘As for Venus, the dates of Mercurial transits are spaced by six months: they all fall within a few days of May 8 and November 10.’
    • ‘The agate stones have a very earthy, grounding influence, which can be invaluable to the Mercurial personality.’
    • ‘The Ascendant to quintile Mercury suggests that he ‘should now have rectified his books of accounts and receive much benefit from Mercurial men’.’
    • ‘I'm not saying those turning points are punctuated by Mercurial storms like I was some Greek hero or something.’
    • ‘The odour of Mercurial herbs is described as ‘highly subtle and penetrating, refreshing to the heart and brain.’’
    • ‘Tejat and Dirah are both located in the left foot of Pollux, so traditionally share the Mercurial / Venus nature.’
    • ‘Modern authors also note the Mercurial influence.’
    • ‘Uranian mind-vibes can sometimes get Mercurial Virgos overwrought and on edge.’


  • A drug or other compound containing mercury.

    ‘for twenty years organic mercurials were the most potent diuretics in clinical use’
    • ‘Inhibition of water flow by mercurials in membrane vesicles, individual root cells and whole root systems points to the importance of aquaporins in the regulation of water flow through root systems.’
    • ‘Results from experiments with mercurials must be viewed with caution because mercury also blocks the pores of other transmembrane proteins, some of which are involved in ion transport.’
    • ‘Before the cancellation of the volatile mercurials, fungicides for treating seed were generally classified as volatile and non-volatile.’
    • ‘Special multiwall or tightly woven bags are recommended for seed that has been treated with mercurials or similarly toxic substances.’
    • ‘A few attempts have been made to demonstrate the action of water channels in roots such as by closing them with mercurials.’
    • ‘In rice seedlings, the application of mercurials had an effect on whole plant conductance only when plants were water stressed by the presence of polyethylene glycol, but not in control growth conditions.’
    • ‘None of the subjects had a history of occupational exposure to Hg and mercurials, symptoms resulting from disorders of the digestive system, amalgam fillings, or experienced digestive-system surgery.’
    • ‘In refractory HF with anasarca, hyperchloremic acidosis was induced to potentiate the effect of intravenous mercurials.’


Late Middle English (in mercurial): from Latin mercurialis relating to the god Mercury, from Mercurius Mercury. mercurial dates from the mid 17th century.