Try "nexus".
point person, liaison
An osculator is a surface that touches (or kisses) another so that they share a tangent at the point of contact.
Condensation point
Associate
detail
Taking Aim
Perspective.
Point.
In physics, a contact force is a force that acts at the point of contact between two objects A contact force is a force applied to a body by another body that is in contact with it.
main idea
convey
I think the word you want is 'nadir' ---------------------------------------------- bottom