Short Words:
* a
* an
* and
* any
* ape
* can
* cone
* dean
* die
* do
* don
* eon
* ice
* in
* ion
* is
* it
* ode
* one
* on
* pen
* pod
* son
* tan
* the
* to
* up
* use
* we
Medium Words:
* canid
* coin
* cynic
* den
* dice
* end
* knee
* nice
* nod
* none
* nope
* open
* pane
* pine
* pod
* pond
* rope
* seed
* tone
* upon
Longer Words:
* condone
* depone
* enclose
* encode
* endue
* opinion
* penned
* poised
* second
* uncoiled
And a few bonus, slightly more obscure words:
* coined
* cycled
* decoy
* doyen
* penile
This list isn't exhaustive, but it provides a good starting point for word-making fun!