"one of ten men," especially as the title of members of several bodies at different times and for different purposes in ancient Rome, mid-15c., from Latin decemvir (plural decemviri), from decem "ten" (from PIE root *dekm- "ten") + vir "man" (from PIE root *wi-ro- "man").
deceitful
deceive
decelerate
deceleration
December
decemvir
decency
decennial
decennoval
decent
decentralization