The term 'LONG, ANGRY COMPLAINT' can be summarized by two crossword solutions: SCREED (6 letters) and RANT (4 letters). A SCREED is a long, passionate speech or written work that expresses strong feelings of anger or indignation. It is often used to criticize or protest something. A RANT is a similar expression of strong emotion, but it is usually more intense and less organized than a SCREED. Both terms are used to describe a lengthy and emotional complaint.