the GNU version of the Collaborative International Dictionary of English
ad. In a rational manner.
The Century Dictionary and Cyclopedia
In a rational manner; in consistency with reason; reasonably: as, to speak rationally; to behave rationally.
In mathematics, as a rational function.
According to ratios or proportions.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
ad. in a rational manner
Word Usage
"These groups do not behave in our sense of the term rationally, and frankly, I'm absolutely astounded if anybody can say if they didn't have chemical or biological weapons, which we call poor man's nuclear weapons."