Here are some possible words:

pac
pad
pal
pan
pap
par
pas
pat
paw
pax
pay
pbx
pct
pea
ped
pee
peg
pen
pep
per
pet
pew
phi
pie
pig
pin
pip
pit
pix
pkg
ply
pod
poi
pol
pop
pot
pow
pox
ppd
pre
pro
prs
pry
psf
psi
pts
pub
pud
pug
pun
pup
pus
put
pyx