As a noun, the list of weblogs (blogs) on your blog that you like, or otherwise want to commend.
As a verb, the tactic of listing another's weblog in the hope that this will induce them to link to yours. Cf. if you don't go to other people's funerals, they won't come to yours.
(verb) to find another person with the same name has stolen the URL of your name or your blog
John Smith goes to set up a blog at (say) blogger.johnsmith.com to find (scandal!) that it's already in use by another &*&(*&! John Smith for HIS blog.
A list of blogs that if, printed out, would supply you with enough loo paper for the next 10 years. Blogroll, due to it's shitty nature, makes excellent loo paper due to the universal law of attraction of similar particles.
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi