The American Heritage® Dictionary of the English Language: Fourth Edition. 2000.
Appendix I
Indo-European Roots
ENTRY:
ser-2
DEFINITION:
To line up. 1.series, sertularian; assert, desert3, dissertate, exert, exsert, insert, from Latin serere, to arrange, attach, join (in speech), discuss. 2. Suffixed form *ser-mon-.sermon, from Latin serm (stem sermn-), speech, discourse. 3. Perhaps suffixed form *ser--.sear2, serried, from Latin sera, a lock, bolt, bar (? < “that which aligns”). 4. Suffixed zero-grade form *s-ti-.sorcerer, sort; assort, consort, ensorcel, sortilege, from Latin sors (stem sort-), lot, fortune (perhaps from the lining up of lots before drawing). (Pokorny 4. ser- 911.)
(stem serm
-. sear2, serried, from Latin sera, a lock, bolt, bar (? < “that which aligns”). 4. Suffixed zero-grade form *s
-ti-. sorcerer, sort; assort, consort, ensorcel, sortilege, from Latin sors (stem sort-), lot, fortune (perhaps from the lining up of lots before drawing). (Pokorny 4. ser- 911.) 
