\Il"la*tive\, a. [L. illativus: cf. F. illatif.]
Relating to, dependent on, or denoting, illation;
inferential; conclusive; as, an illative consequence or
proposition; an illative word, as then, therefore, etc.
{Illative conversion} (Logic), a converse or reverse
   statement of a proposition which in that form must be true
   because the original proposition is true.
{Illative sense} (Metaph.), the faculty of the mind by which
   it apprehends the conditions and determines upon the
   correctness of inferences.

\Il"la*tive\, n.
An illative particle, as for, because.