pattern - What is a Rotten Word™?

_{This is in the spirit of the What is a Word/Phrase™ series started by JLee with a special brand of Phrase™ and Word™ puzzles.}

If a word conforms to a special rule, I call it a Rotten Word™.

Use the following examples below to find the rule.

And, if you want to analyze, here is a CSV version:

Rotten Words™,Not Rotten Words™

ANT,BEETLE
BARF,VOMIT
CLERK,TELLER
EBBS,FLOWS
ENVY,JEALOUSY
FLAP,FLUTTER
GNAT,FLY
GREEN,BLUE
NOWHERE,SOMEWHERE
NUN,PRIEST

PURELY,MIXED
REEF,OCEAN
ROOF,CEILING
VEX,TROUBLE

Answer

Rotten Words are words that...

can be ROT13'd to produce a new word. (A is replaced with N B with O, etc.)
These produce: NAG ONES PYREX ROOF RAIL SYNC TANG TERRA ABJURER AHA CHERYL ERRS EBBS IRK.