1se·ri·al 
/ˈsirijəl/ adjective
always used before a noun /ˈsirijəl/ adjective 1 : arranged or happening in a series
▪ The pictures are numbered and arranged in serial order. ▪ Scientists made serial observations over a period of two weeks. 2 a of a crime : committed many times usually in the same way
▪ serial murders/rapes
b of a criminal : committing a series of crimes
▪ a serial killer/rapist 3 : broadcast or published in separate parts over a period of time
▪ a serial story/novel/publication 4 computers : designed for a computer system in which very small pieces of information are sent one at a time over a single wire
▪ a serial cable/connection/port/printer — compare 1parallel 3
▪ The pictures are numbered and arranged in serial order. ▪ Scientists made serial observations over a period of two weeks.
▪ serial murders/rapes
b of a criminal : committing a series of crimes
▪ a serial killer/rapist
▪ a serial story/novel/publication
▪ a serial cable/connection/port/printer — compare 1parallel 3
— se·ri·al·ly adverb
▪ serially numbered items ▪ serially connected printers ▪ The story was published serially.
▪ serially numbered items ▪ serially connected printers ▪ The story was published serially.
