Definition of formatives:
(adj) :
Capable of forming something.
(adj) :
Of or pertaining to the formation and subsequent growth of something.
(adj) :
(education) Of a form of assessment: used to guide learning rather than to quantify educational outcomes.
(adj) :
(biology) Capable of producing new tissue.
(adj) :
(linguistic morphology) Pertaining to the formation of words; specifically, of an affix: forming words through inflection.
(n) :
(linguistic morphology) A language unit, typically a morph, that has a morphological function (that is, forming a word from a root or another word).