What does “eu” mean? As in EUlogy, EUphony, EUgenics?
see below
The prefix -eu means good, pleasant, or well.
Eulogy is an oral or written piece telling about good or pleasant things about a dead person.
Euphony is a quality that means pleasing to the ear.
Eugenics is the science of breeding human population in order to produce desirable, heritable characteristics.