About 0.3% of words in an English
dictionary have this property, including
ait,
bijou,
dekko,
dotty, and
horst. The first is
aah and the last is
tux; the longest are
beefily and
billowy.
With all their letters in reverse alphabetical order, the first and last are baa and zymic, the longest are spoonfed and trollied.
Information extracted with a Perl script by Anu Garg, aka Wordsmith, the Nate-figure of a site called A.Word.A.Day for all your (English-)language curiosity.