adjective mer·cu·ri·al \(ˌ)mər-ˈkyr-ē-əl\

: changing moods quickly and often

: changing often : very changeable

: very lively and quick

Full Definition of MERCURIAL

:  of, relating to, or born under the planet Mercury
:  having qualities of eloquence, ingenuity, or thievishness attributed to the god Mercury or to the influence of the planet Mercury
:  characterized by rapid and unpredictable changeableness of mood <a mercurial temper>
:  of, relating to, containing, or caused by mercury
mer·cu·ri·al·ly \-ē-ə-lē\ adverb
mer·cu·ri·al·ness noun

Examples of MERCURIAL

  1. <the boss's mood is so mercurial that we never know how he's going to react to anything>
  2. Few moments in English history have been more hungry for the future, its mercurial possibilities and its hope of richness, than the spring of 1603. —Adam Nicolson, God's Secretaries, 2003


(see mercury)
First Known Use: 14th century

Synonym Discussion of MERCURIAL

inconstant, fickle, capricious, mercurial, unstable mean lacking firmness or steadiness (as in purpose or devotion). inconstant implies an incapacity for steadiness and an inherent tendency to change <an inconstant friend>. fickle suggests unreliability because of perverse changeability and incapacity for steadfastness <performers discover how fickle fans can be>. capricious suggests motivation by sudden whim or fancy and stresses unpredictability <an utterly capricious critic>. mercurial implies a rapid changeability in mood <made anxious by her boss's mercurial temperament>. unstable implies an incapacity for remaining in a fixed position or steady course and applies especially to a lack of emotional balance <too unstable to hold a job>.

Rhymes with MERCURIAL


noun mer·cu·ri·al \(ˌ)mər-ˈkyr-ē-əl\

Definition of MERCURIAL

:  a pharmaceutical or chemical containing mercury


(see mercury)
First Known Use: 1676

Other Chemical Engineering Terms

alkali, cation, decant, hygroscopic, isotope, oxidize, slurry, solute, viscous


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