A removable singularity is a singular point 
of a function 
for which it is possible to assign
a complex number in such a way that 
becomes analytic.
A more precise way of defining a removable singularity is as a singularity 
of a function 
about which the function 
is bounded. For example, the point 
is a removable singularity in the sinc
function 
,
since this function satisfies 
.
Removable Singularity
See also
Essential Singularity, Pole, Removable Discontinuity, Riemann Removable Singularity Theorem, Singular PointExplore with Wolfram|Alpha
References
Krantz, S. G. "Removable Singularities, Poles, and Essential Singularities." §4.1.4 in Handbook of Complex Variables. Boston, MA: Birkhäuser, p. 42, 1999.Referenced on Wolfram|Alpha
Removable SingularityCite this as:
Weisstein, Eric W. "Removable Singularity." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/RemovableSingularity.html