The nene is a goose, not a duck.
And another possibility for the sacred prefix is “hiero.”
twicks, puzzle editor
I’ve also seen it as tern, but can’t remember seeing it as terne anywhere.
And to add a couple more common crossword answers to the list: an “epee” is a fencing sword and “Esau” was Jacob’s brother.
While all these suggestions are good, I should note that puzzle writers these days (at least the really good ones) are trying to get away from the really obscure clues/words that exist only for the convenient letter formation. So YMMV when it comes to the usefulness of these.
Another ‘WW2 Brit gun (4)’: Bren. Sacro- and hiero- are possible prefixes meaning ‘sacred’. There’s one more I can think of: hagio-, which means ‘holy’ or ‘referring to the saints’ (hagiography, Hagia Sophia).
For those of you who are fans of the NY Times puzzle - it is now available on-line from the NY Times as a Java application. You pay about $34 a year for it. I love it. You can do the daily puzzle on-line, or print it on paper and do it in pencil. You can save a partially finished puzzle and complete it later. You can race against the clock. You can complete with others to see who finished it first. If this isn’t a great use of technology, I don’t know what is. Go here to see it.
The New York Times typically uses “directional suffix” as a clue for ern, or maybe I’m only seeing that as I’m a wimp who only does the puzzles early in the week…
It actually ended up being heiro. You’re good!
Can you recommend any good sites on crossword construction? It seems like it would be really interesting. Also, please give me your home address so I can send you all my puzzles for editing. 
Sorry – didn’t see your post. (Should I admit I do a vanity search once a week or so?)
Here are some links you might find helpful. I use custom-written software at work, so have no recommendations about the “OTC” programs.
If you’d like to get in touch, my email address is in my profile – put “SDMB” in the message line so I don’t delete it as spam.
I haven’t written any new crossword puzzles in several years, but I used to write them regularly, and got dozens of them published. So, I can tell you first hand that most editors will immediately reject puzzles that use more than one of the cliche “crosswordese” entries people have been ridiculing here.
On one hand, I applaud them for upping their standards. At the same time, I know from experience how hard it can be to avoid using those cliches! There are only so many 3 and 4 letter words that use the most common letters of the alphabet, and it’s VERY easy to get stuck in a corner where “ESNE” or "ERNE " or “UTA” (Hagen) or “STEN” or “ETE” (French summer) is the only thing you can enter to make the puzzle work.
From the Guardian newspaper crossword:
gegs (two words; 9 + 4 letters)
dead boring (11 letters)
From me:
postman’s sack
Sorry folks, the only real crosswords puzzles are cryptic crosswords. Sample clue:
Help mixed-up car company with calm fortitude.
Answer: phlegm
gegs (two words; 9 + 4 letters)SCRAMBLED EGGS
dead boring (11 letters)NECROPHILIA
postman’s sackSCROTUM
Nice one!
I don’t get the “calm fortitude” part.
From Dictionary.com:
phlegm ( P ) Pronunciation Key (flm)
n.
Thick, sticky, stringy mucus secreted by the mucous membrane of the respiratory tract, as during a cold or other respiratory infection.
One of the four humors of ancient and medieval physiology, thought to cause sluggishness, apathy, and evenness of temper.
Sluggishness of temperament.
Calm self-possession; equanimity.
I just knew when I asked there would be a :smack: - D’oh! moment at the end of it. But still I had to ask. I wasn’t thinking of phlegmatic, which I know the definition of, thank you, I was wondering how GM had “calm fortitude”. :o
Daniel
First two answers correct (well done, that man 
).
Alas, the third is wrong.
Would you like more information?