look up any word, like fellated:
 
1.
A bad situation or behavior that is the cause of another situation (or causal chain) which in turn causes the first, bad situation again.

A positive feedback loop in which the result is bad.
A vicious cycle in "The Little Prince":

'I am drinking,' answered the drunkard lugubriously.
'Why are you drinking?' the little prince asked.
'In order to forget,' replied the drunkard.
'To forget what?' enquired the little prince, who was already feeling sorry for him.
'To forget that I am ashamed,' the drunkard confessed, hanging his head.
'Ashamed of what?' asked the little prince who wanted to help him.
'Ashamed of drinking!' concluded the drunkard, withdrawing into total silence.


- Antoine de Saint-Exupery
by dreamlandburns August 27, 2008
 
2.
A circular process that requires one to do perform an action that has some effect and as a result requires the same action to be done again.
Every time I pulled a tissue out of the box more dust was stirred up which caused me to require yet another tissue- a vicious cycle.

The more sweets I ate the more my sweet tooth grew.
by GKBono September 21, 2006
 
3.
another name for the original term "vicious circle".
Some people like to use the term "vicious cycle" when they mean "vicious circle", because "cycle" and "circle" sound familiar, but the correct terminology is "vicious circle"
by Tex01 November 18, 2007