Let 
be a link in 
and let there be a disk 
in the link complement 
. Then a surface 
such that 
intersects 
exactly in its boundary and its boundary does not bound another
disk on 
is called a compressible surface (Adams 1994, p. 86).
Compressible Surface
See also
Knot ComplementExplore with Wolfram|Alpha
References
Adams, C. C. The Knot Book: An Elementary Introduction to the Mathematical Theory of Knots. New York: W. H. Freeman, 1994.Referenced on Wolfram|Alpha
Compressible SurfaceCite this as:
Weisstein, Eric W. "Compressible Surface." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/CompressibleSurface.html