To rotate a point \((x, y)\) clockwise by 90 degrees about the origin, the transformation can be applied as follows:
\[ (x, y) \rightarrow (y, -x) \]
For the point \((-4, -6)\), we can substitute \(x = -4\) and \(y = -6\):
\[ (-4, -6) \rightarrow (-6, -(-4)) = (-6, 4) \]
Thus, the new point after rotating \((-4, -6)\) clockwise 90 degrees about the origin is:
\[ \boxed{(-6, 4)} \]