col (saddle point)

https://doi.org/10.1351/goldbook.C01145
A mountain-pass in a @P04780@ is known as a col or @S05446@. It is a point at which the @G02669@ is zero along all coordinates, and the curvature is positive along all but one coordinate, which is the @R05168@, along which the curvature is negative.
Source:
PAC, 1996, 68, 149. (A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC Recommendations 1996)) on page 158 [Terms] [Paper]