preposterous
Some 10 letter P words:partialityparticularpermissionpersonallyprecautionpresupposepronouncedproportionprejudicedproportionprefermentprepaymentpreachmentplacementspracticingpercentileproductivepermissiveprovisionsprotectionprovention
procrastinate
pepperoni
Primper.
pi
phenomenal
There are no 23 letter words in the English language starting with the letter p.
prize
plaza
Pepsi
pressed
peon