a term used by Leibnitz for the act whereby the mind becomes conscious of its perceptions.

AD pondus omnium, among physicians, an abbreviation in their prescriptions, signifying that the last mentioned ingredient is to weigh as much as all the rest together.

AD quod damnum, in the English law, a writ directed to the sheriff, commanding him to enquire into the damage which may befall from granting certain privileges to a place, as a fair, market, or the like.