-ion Also -cion, -sion, -tion, and -xion.
Forming nouns denoting verbal action.
[Via French from Latin -ion- or words in -io.]
Examples have been formed from Latin verbs, adjectives or past participles. The main sense is that of an action related to a verb, as communion is the action of communing; rebellion is similarly related to the verb to rebel, fusion to fuse, and infliction to inflict. Nouns can often refer as much to a condition resulting from an action as to the action itself, as pollution can be the action of polluting, or the presence of some harmful substance as a result of the action. In some cases, the noun refers more particularly to the result rather than the action, as in explosion.
Many examples are preceded by a letter derived from the stem of the Latin participle: mainly s (immersion, persuasion) or t (evolution, solution), less often by c (suspicion) or x (fluxion).
A small group derived from Latin nouns have variously been spelled either -xion or -ction. With a few, the first spelling is standard (complexion, transfixion). With others both forms exist (connection/connexion; inflection/inflexion); in these cases the spelling in -ction predominates, partly because of the way the associated verb is spelled (connect, inflect) but also because there are so many nouns in -tion that this spelling has influenced them.