This is an irresponsible question: I do not have done any thinking on it, or even literature search.
I just became curious whether there is some modification of the notion of a common root of two polynomials which would be detected by a Pfaffian of some alternate matrix, rather than a determinant of some general matrix, like it is the case with the resultant.
(PS Seems like there is no tag "algebra", so I chose commutative algebra instead)