Inflection [technica flexiva] is a morphological technique of expressing grammatical meanings on a word by change of the latter. The different inflectional categories typically have no morphological expression of their own, but are encoded by means of one grammatical formative or morphological modification of the stem.

This 19^th cent. concept of inflection differs from the 20^th cent. concept, here named ‘inflection [vs. derivation]’.