Valency

Part of speech: noun

Pronunciation: /ˈveɪlənsi/

Definitions

1. The capacity of an element to combine with other atoms through chemical bonds ; the number of arguments a verb requires in a sentence structure
2. A measure of how many atoms one atom can bond with in chemistry ; the count of participants needed by a verb to form a complete clause
3. The ability of a chemical element to bond with others by sharing or exchanging electrons ; the number of roles a verb assigns to its associated nouns in grammar

Etymology: The word's most surprising feature is that its chemistry sense is a figure of speech borrowed from a physical one. Latin "valentia" meant bodily strength, health and vigour, and it grew from "valēns", "healthy, strong, vigorous", the form of the verb "valeō", "to be strong, to have influence or power." Long before anyone counted electrons, the idea of a thing's power to act was already in the Latin. The chemical meaning, the capacity of an atom to combine with others, came from that notion of power or strength. The grammatical sense, the number of arguments a verb can take, seems to have arrived by the same route, as a metaphor for how many partners a verb is able to govern. Both senses likely draw on the English suffix "-y", which forms abstract nouns of condition or quality, attached to the earlier "valence."

Synonyms: valence