- phallus15
- philadelphus26
- phoebus16
- phosphorous22
- phosphorus21
- phycomycetous32
- phytophagous27
- piceous14
- picornavirus24
- pignus13
- pilaus11
- pileous12
- pileus11
- pilous11
- pilus10
- pious9
- pirarucus17
- piscivorous22
- piteous11
- pithecanthropus30
- plateaus13
- platitudinous21
- platypus18
- plenitudinous22
- plenteous15
- plexus18
- plumbous20
- plunderous18
- plus9
- pluteus13
- pluvious18
- pneumococcus30
- poaceous15
- poilus11
- poisonous14
- poliovirus19
- polyandrous20
- polyanthus20
- polychotomous28
- polyestrous18
- polygamous22
- polygynous22
- polymorphous27
- polyonymous24
- polypetalous23
- polyphagous25
- polyphonous24
- polypous18
- polypus17
- polysemous20
- polystichous24
- pomaceous19
- pompous17
- ponderous15
- populous17
- porcelaneous21
- porcellaneous23
- porous10
- portentous15
- portmanteaus20
- posthumous20
- poststimulus21
- poxvirus23
- poyous12
- prahus12
- praus9
- precalculus24
- precancerous23
- precarious17
- precious15
- precipitous21
- precocious20
- preconscious23
- predaceous18
- predacious18
- prefocus18
- preposterous19
- prestigious17
- presumptuous24
- pretentious16
- previous16
- priapus14
- priedieus14
- primiparous21
- primus13
- prodigious17
- proestrus13
- prognathous20
- prolegomenous24
- promiscuous22
- pronucleus20
- propitious17
- propositus17
- prospectus20
- prosperous17
- proteinaceous21
- proteus11
- prothallus18
- proventriculus28
- provirus16
- prunus12
- pruritus13
- pseudomorphous28
- pseudonymous24
- pseudoparenchymatous40
- pugnacious21
- pulchritudinous29
- pulpous16
- pulvillus21
- pulvinus19
- pumiceous20
- punctilious21
- purlieus14
- pus7
- pusillanimous24
- pylorus14
- pyritous14
- quadrumanous29
- querulous22
- quietus18
- quippus24
- quipus20
- racemous15
- radius8
- railbus12
- rambunctious24
- ramous10
- rampageous19
- ramulous14
- ramus9
- rancorous14
- ranunculus19
- rapacious16
- rapturous14
- raucous12
- ravenous14
- rebellious16
- rebus9
- rectitudinous20
- rectus10
- redivivus19
- refocus14
- regius9
- regulus12
- religious13
- rendezvous26
- reovirus13
- repetitious15
- reseaus8
- resinous10
- retiarius10
- retrovirus15
- rhabdovirus22
- rhamnus14
- rhesus9
- rhinovirus18
- rhizomatous26
- rhizopus23
- rhomboideus21
- rhombus16
- rhonchus17
- rhus7
- ricinus12
- rictus10
- ridiculous17
- righteous14
- rigorous11
- rimous10
- riotous8
- risus6
- rivalrous15
- robustious15
- roisterous11
- rosaceous13
- rosinous10
- rotavirus14
- rouleaus11
- rousseaus11
- rubious12
- rubus10
- ruckus15
- ructious13
- rufous11
- rugous10
- ruinous10
- rumbustious20
- rumpus14
- sabulous14
- sacculus17
- sacrilegious19
- saddhus12
- sadhus10
- sagacious15
- sajous16
- salacious14
- saleratus11
- salubrious16
- salutiferous18
- samshus13
- sanctimonious22