Malone, my point was that the required word should have been defined exactly as per Chambers to be fair to solvers. I was sure MIGRATING was the right word because of the exact wording in Chambers. I thought some sort of word chain was involved, getting from PIG to RAT via MIG, which might be applied somehow to the unclued entries.
Orson, I'm not sure your point about speaking the words applies because the pig Latin is actually the real word, not the entry.