Eeeeeyeeeeuuuuwwww

'eu-', the little Greek prefix, that could.
In combinational form, it modifies as
'well' & 'easily.'

So, let's try Eucalyptus.
eu + (the Greek) kaluptos (covered) = 'well covered'.
The unopened flower of the Eucalyptus Tree is protected by a cap.

Here's a good one: Eudemonic.
eu + daimon (guardian spirit) = happy.
Eudemonism is a system of ethics that bases moral obligation on the likelihood of actions producing happiness.
Eudemonic - conducive to happiness.

Eugenics is a modern word. Skip it.

Eunuch.
This one's got me nipped. I'll need to learn more Greek.
The etymology is eu + noukhos; with a literal translation as, 'bedchamber attendant.' What's a 'noukhos?'

Eupeptic, Euphemism, Eulogy, Europa....
they all come alive,
when you focus on the eu.

And have the Eurythmics ever played an euphonium?