In English, are there any words which encrypt to other words under the Caesar Cipher?
Actually, we have a four-way (that is, four words that will can be converted into any of the others with the right shift).  These words are:

ax, by, he, if


Other two letter words are:

am &lt;-&gt; my
at &lt;-&gt; pi
do &lt;-&gt; it
hi &lt;-&gt; no


We also have

the &lt;-&gt; max


I didn't do a systematic search for words over two letters; there certainly do appear that they are moderately plentiful



I've done a more systematic search over longer words; ignoring extremely obscure words, the best I found were

abjurer &lt;-&gt; nowhere
inkier &lt;-&gt; purply
fusion &lt;-&gt; layout
manful &lt;-&gt; thumbs
primero &lt;-&gt; sulphur
steeds &lt;-&gt; tuffet


(OK, 'tuffet' missed by 'obscure' criteria; I still liked it).

So, yes, there certainly are words can be be encoded into other words