@var{definition} should have the form
@example
-(advice . @var{LAMBDA})
+(advice . @var{lambda})
@end example
@noindent
-where @var{LAMBDA} is a lambda expression that is evaluated to run the
-advice. @xref{Lambda Expressions}.
+where @var{lambda} is a lambda expression; this lambda expression is
+called in order to perform the advice. @xref{Lambda Expressions}.
If the @var{function} argument to @code{ad-add-advice} already has one
or more pieces of advice in the specified @var{class}, then