Pronunciation: (pri-zump'tiv), [key]
1. affording ground for presumption: presumptive evidence.
2. based on presumption: a presumptive title.
3. regarded as such by presumption; based on inference.
4. Embryol.pertaining to the part of an embryo that, in the course of normal development, will predictably become a particular structure or region.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.