I'm often asked whether Solaris has an index for commands or not. If the /usr/share/man/windex database exists, it does. The apropos command is used to perform the lookups. Here's an example.
If /usr/share/man/windex doesn't exist, use the following command to build the database: #catman -w
Otherwise
#apropos shadow
The apropos command has the same output as the man -k pattern.