Definition of valency in English:



  • 1The combining power of an element, especially as measured by the number of hydrogen atoms it can displace or combine with.

    ‘carbon always has a valency of 4’
    Compare with valence
    • ‘Plutonium has five different crystal-type conditions or ‘phases’ that it can be in, and has five possible valencies.’
    • ‘The higher the valency of the counterions, the more significant is the reversal of the effective charge of the aggregates.’
    • ‘Depending on the charges of additional groups that may be bound to the phosphate group, phospholipids in water can have a valency between - 2 and + 1, and also neutral groups are possible.’
    • ‘It is well-known that aggregation can be induced by changes in pH, the salt concentration, valency of ions, or the polarity of the solvent.’
    • ‘The degree of flocculation, and hence randomness of particle orientations on sedimentation, generally increases with the concentration and valency of the cations in the solution.’
    1. 1.1Linguistics
      The number of grammatical elements with which a particular word, especially a verb, combines in a sentence.
      ‘‘give’ has a valency of three in ‘I (1) gave it (2) to him (3)’’
      • ‘The purpose of this paper is to study the factors involved in the changing valency of the reflexes of ABHORRERE / ABHORRESCERE in Castilian, ie aborrir ~ aburrir and aborre cer.’


Early 17th century: from late Latin valentia power, competence, from valere be well or strong.