ebullient

(n) the quality of lively or enthusiastic expression of thoughts or feelings   
The bull was full of ebullience, bucking all day and wanting to escape its pen to hang out with the cows.

eclectic

(adj) selecting what appears to be best in various doctrines, methods, or styles  
Rina had eclectic interests, ranging from fishing to web design.

efficacy

(n) the power to produce an effect    
The bridge builder was as full of efficacy at his craft as Michelangelo was at sculpting.

effrontery

(n) shameless boldness.  
The two warring countries' leaders acted with effrontery towards one another.

elegy

(n)  a song or poem expressing sorrow or lamentation especially for one who is dead.   
The somber breakup song was about as sad as a Romantic period elegy.

elicit

(v) to draw forth or bring out   
Every February crazy people in Pennsylvania try to elicit a groundhog from a hole.

eloquent

(adj) marked by forceful and fluent expression   
The street preacher was as eloquent as any mega church preacher and caused even a stray passer-by to stop and listen.

embellish

(v) to enhance or adorn  
Grandpa always embellished his stories. The fish he said he caught got bigger each year.

emollient

(adj) making less intense or harsh : mollifying.   
The Neosporin had an emollient effect on Johnny's cut almost as good as Tylenol does for headaches.

empirical

(adj) originating in or based on observation or experience   
The English teacher's demand for concision was almost as strict as my science teacher's demand for empirical, laboratory-tested evidence.

emulate

(v) to imitate.  
Gerry liked her math teacher so much she wanted to emulate her career and also become a math teacher.

endemic

(adj) belonging or native to a particular people or country   
Although we think of Weeping Willow trees as endemic to North America, they were actually imported here from Asia a while ago.

enervate

(adj) lacking physical, mental, or moral vigor   
Discouraged after failing two tests, Hector was too enervated to take a third.

engender

(v) to cause to exist or to develop; to beget   
A-Rod engenders good hitting skills upon his teammates. They learn from his style.

enigmatic

(adj) mysterious  
Enya, the wispy whisper-singer, was enigmatic because you'd hardly ever see her in public.

ennui

(n) a feeling of weariness and dissatisfaction; boredom   
Albert Camus, who wrote about disaffected characters, was probably himself prone to ennui.

ephemeral

(adj) lasting a very short time  
The Northern lights were awesome but so ephemeral, lasting only a few minutes per night.

equanimity

(n) evenness of mind especially under stress   
After a lot of studying for the GRE, I felt as full of equanimity during the test like a general well-prepared for battle.

equivocate

(v) to avoid committing oneself in what one say
The presidential candidate wanted to be all things to all people, so he often equivocated when asked about difficult issues.

erudite

(adj) learned; book smart   
The professor was erudite and published a lot of books, but didn’t have the kind of smarts to cross the street.