noun

1. the act of presuming; specif.,
   1. an overstepping of proper bounds; forwardness; effrontery
   2. the taking of something for granted
2. the thing presumed; supposition
3. a ground or reason for presuming; evidence that points to the probability of something
4. Law the inference that a fact exists, based on the proved existence of other facts

Etymology: ME < OFr presumpcion < L praesumptio, a taking beforehand < praesumptus, pp. of praesumere: see presume