tangency

• tangence (relatively rare)

tangency (countable and uncountable, plural tangencies)

1. The state of being tangent; an instance of (something) being tangent.
   • 1999, H. Flenner, L. O′Carroll, W. Vogel, Joins and Intersections, page 131:

     In this section we will apply the concept of connectedness in dimension d to study tangencies of algebraic varieties.

   • 2004, David A. Madsen et al., Engineering Drawing & Design, 3rd edition, page 160:

     To be tangent to a circle or arc, a line must touch the circle or arc at only one point, and a line drawn from the center of the circle or arc must be perpendicular to the tangent line at the point of tangency. (See Figure 6.82.)

   • 2011, Steven E. Landsburg, Price Theory and Applications, 8th edition, page 83:

     If the original tangency is at A, then the new tangency cannot be at O or P, as either possibility would require two indifference curves to cross. […] Instead, the new tangency is at a point like B.

• point of tangency
• tangency portfolio

• transversality