Picture, parlous, pikelet, pannier, pliable, panther, pollute, pottage.
pepperoni oops- 9 letters
Propose... There may be more....
Sp
Primper.
pitcher
prepare
Teashop treetop trollop .
pablum
Some 10 letter P words:partialityparticularpermissionpersonallyprecautionpresupposepronouncedproportionprejudicedproportionprefermentprepaymentpreachmentplacementspracticingpercentileproductivepermissiveprovisionsprotectionprovention
procrastinate
pi
preposterous
pepperoni
phenomenal
There are no 23 letter words in the English language starting with the letter p.