Sator squares

In high school, my mom showed me the Sator square:

SATOR
AREPO
TENET
OPERA
ROTAS

The oldest known copy was found on a wall in Pompeii:

They are all real Latin five-letter words, the words going down read the same as the words going across, and the bottom three words are the top three words reversed (so the middle word is a palindrome). I understand that it is also a legitimate sentence in Latin?

I wondered, at the time, if such a square existed in English. I tried working it out by hand, and came up with these two:

PARTS
APART
RADAR
TRAP A
STRAP

WARTS
APART
RADAR
TRAP A
STRAW

Of course, TRAP A is two words, so it wasn't perfect. That's where I left it. Today I decided to try writing a program to find them. It starts with a word list, then ranks the results by word frequency. I was surprised that these same two were the top of the list-- apparently, "trapa" is the scientific term for water chestnut. Here are some of the other top results:

HARAS
AROMA
ROTOR
AMORA
SARAH

"Haras" is a horse stud farm. "Amora" is the name of a rabbi.

MELAS
ENEMA
LEVEL
AMENE
SALEM

"Amene" is pleasant. "MELAS" is an acronym for a neurological condition.

STATS
TENET
ANANA
TENET
STATS

"anana" (usually ananas, which I did know) is the genus for pineapple plants. This is all palindromes, which is probably less interesting.

You get the idea. There are 500-600 of this sort, all with at least one word so rare that I don't know it.

I wondered if I allowed combinations of 1 and 4 letter words, like "trap a" if I could find any better results. I decided that one of the directions would still have to be a 5-letter word. This kept the number to look through down to a reasonable level. I also ranked the squares by the minimum of the zipf scores for each line, figuring that a poor word should be disqualifying for the square as a whole.

Here are some of the better results of this relaxed method:

DECAL
EVIL A
CIVIC
ALIVE
LACED

S DRAW
DIANA
RADAR
AN AID
WARDS

MARAH
ARENA
REFER
AN ERA
HARAM

HE-MAN
EVIL A
MINIM
ALIVE
NAME H