diff --git a/docs/source/io_formats/settings.rst b/docs/source/io_formats/settings.rst
index a5cf36ece..1a8f63716 100644
--- a/docs/source/io_formats/settings.rst
+++ b/docs/source/io_formats/settings.rst
@@ -491,7 +491,7 @@ attributes/sub-elements:
       azimuthal angle and the origin for the cylindrical coordinate system is
       specified by origin. A "spherical" spatial distribution specifies
       independent distributions of r-, cos_theta-, and phi-coordinates where
-      cos_theta is the cosinus of the angle with respect to the z-axis, phi is
+      cos_theta is the cosine of the angle with respect to the z-axis, phi is
       the azimuthal angle, and the sphere is centered on the coordinate
       (x0,y0,z0).