If they tell you sei un fannullone (pronounced fahn-nool-loh-neh) you should either reconsider the people you hang  with or your work ethics.  While fannullone may sound pretty funny, with  all those double  consonants and the -one ending — doesn’t it make  you think of something cuddly?— its meaning is not that pleasant, especially when they use the word to talk about you. 

In Italian, a fannullone is someone who, quite simply, doesn’t like to work, nor engage in any type of activity involving reflection or effort: a slacker, we would say in English.  The word is a relatively recent addition to the  Italian dictionary, as it became popular around the mid-19th century. It comes from two other terms, the verb fare (to do) and the adverb nulla (nothing): so, literally, fannullone  is someone who does nothing.