New word from a rotation function

In the Caesar cipher a word is encoded by rotating the letters in the alphabet a given number of times, $N<26$. A word is the smallest sequence of phonemes that can be uttered in isolation with objective or practical meaning.

Question. What is the longest word with a sence that is obtained after the rotation function rotN()?

For example, if the is the original word then rot19(the)=max is a new word with a sense. The word’s length is 3.

4-letters word: rot23(frog)=cold.