1》 consisting of, forming part of, or taking place in a series.
2》 repeatedly committing the same offence or following a characteristic behaviour pattern: a ~ killer.
3》 Music relating to or using ~ism.
4》 Computing (of a device) involving the transfer of data as a single sequence of bits.
1》 a published or broadcast story or play appearing in regular instalments.
2》 (in a library) a periodical.
C19: from series + -al , perh. suggested by Fr. sérial .