It is part of an idiolect that made popular in Spain the actor Gregorio Sánchez Fernández with his character Chiquito de la Calzada to name "a guy" , "the uncle" , "the type" , "the quia" , and that later remained in the usual vocabulary of the peninsula. The definition of Anonymous is a very personal interpretation of the term, which they say (half seriously, half joking) comes from the Swedish fstrohm (fistro "friend") ; but since it later became a multipurpose mulet, maybe he's right.
* Only one "like" per meaning and day, the more "likes" the meaning will appear higher in the list
