Definition of: formative

(fôr′mə·tiv) adjective
1. Competent, serving, or aiding to form; capable of being formed or influenced; plastic.
2. Pertaining to formation.
3. Gram. Serving to form words.
—noun Gram.
1. An element, as an affix, added to the root of a word to give it a new and special grammatical form.
2. A word formed by the addition of a new element to, or a modification of, the root.