from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A line that is tangent to a curve at two points
from the GNU version of the Collaborative International Dictionary of English
- adj. Possessing the property of touching at two points.
from The Century Dictionary and Cyclopedia
- n. In mathematics, a double tangent; a straight line which touches a given curve at two points.
bi- + tangent (Wiktionary)