fix typo

Doc/tut/glossary.tex

@@ -62,7 +62,7 @@ Python has builtin support for complex numbers, which are written with this
 latter notation; the imaginary part is written with a {}\code{j} suffix,
 e.g., {}\code{3+1j}.  To get access to complex equivalents of the
 {}\module{math} module, use {}\module{cmath}.  Use of complex numbers is a
-fairy advanced mathematical feature.  If you're not aware of a need for them,
+fairly advanced mathematical feature.  If you're not aware of a need for them,
 it's almost certain you can safely ignore them.
 
 \index{descriptor}