English▸ noun Chemistry & Linguistics the combining power of an element, especially as measured by the number of hydrogen atoms it can displace or combine with:
carbon always has a valence of 4.
▪ [as modifier] relating to or denoting electrons involved in or available for chemical bond formation:
molecules with unpaired valence electrons.
▪ Linguistics the number of grammatical elements with which a particular word, especially a verb, combines in a sentence.
– ORIGIN late Middle English : from late Latin valentia ‘power, competence’, from valere ‘be well or strong’.