The term 'pattern of behavior' can refer to a variety of different things. In this case, the crossword solutions for the term are WONT (4 letters) and SYNDROME (8 letters). WONT is an archaic word meaning 'HABIT' or 'CUSTOM, ' while SYNDROME is a medical term used to describe a group of symptoms that occur together and characterize a particular disease or disorder. Together, these two words can be used to describe a pattern of behavior that is either habitual or indicative of a particular disorder.