- operational16
- ophthalmological34
- oppositional20
- optical14
- optimal14
- optional13
- oral5
- oratorical14
- orbital11
- orchestral16
- orchestrational22
- ordeal8
- ordinal10
- organismal17
- organizational28
- organomercurial26
- oriental10
- orientational16
- orificial16
- original12
- orinasal10
- orismological23
- ornamental16
- ornithological24
- orographical23
- oropharyngeal24
- orphical17
- orthogonal16
- orthographical27
- orthonormal18
- oscillational20
- osmolal12
- osteal7
- osteological19
- otolaryngological30
- otorhinolaryngological38
- outgeneral15
- outrival14
- oval9
- ovarial12
- overanalytical26
- overarousal17
- overbrutal19
- overcritical23
- overemotional22
- overliteral17
- overpedal18
- overzeal22
- ovicidal17
- oviducal18
- oviductal19
- ovipositional22
- ovoidal13
- paginal14
- pal7
- palatal12
- palatial13
- paleal11
- paleoanthropological37
- paleobiological29
- paleobotanical26
- paleoecological29
- paleogeographical34
- paleographical29
- paleontological27
- paleopathological33
- paleozoological35
- pallial13
- palpal14
- palpebral20
- paludal14
- palynological27
- panegyrical23
- pansexual22
- pantheistical23
- pantisocratical26
- pantropical22
- papal12
- papyral16
- paraboloidal21
- paradisaical20
- paradisal14
- paradisiacal20
- paradisial15
- paradisical19
- paradoxical26
- paralegal16
- paramedical22
- paranoidal16
- paranormal18
- parapodial18
- paraprofessional27
- parapsychological37
- parasexual22
- parasitical18
- parasiticidal21
- parasitological25
- paratactical22
- parenchymal26
- parental13
- parenteral15
- parenthetical23
- parfocal18
- parietal12
- parochial18
- paroxysmal26
- parral10
- parricidal18
- partial11
- participational26
- participial21
- pascal13
- paschal16
- passional14
- pastoral12
- pastural13
- patagial14
- paternal13
- pathetical19
- pathological24
- pathophysiological37
- patriarchal20
- patricidal18
- patrilineal17
- patrimonial19
- patristical18
- patronal13
- pausal11
- peal8
- pectoral15
- pedagogical23
- pedal10
- pedestal13
- pedimental19
- pedocal15
- pedological22
- pelagial15
- pelletal14
- penal10
- penial11
- penitential17
- pennyroyal20
- penological22
- pentagonal18
- pentahedral19
- pentobarbital24
- penumbral21
- perceptional23
- perceptual21
- perennial15
- pericardial19
- perichondral23
- pericranial19
- peridial13
- perigeal14
- perihelial17
- perikaryal20
- perinatal14
- perineal13
- periodical18
- periodontal17
- periosteal14
- peripheral19
- peristomial18
- perithecial20
- peritoneal15
- permutational22
- peroneal13
- peroral11
- perorational17
- peroxisomal25
- perpetual17
- personal13
- perspectival26
- perturbational23
- perusal12
- pestilential18
- petal9
- petechial18
- petrochemical28
- petrographical28
- petrological22
- petrosal12
- peytral13
- phalangeal20
- phantasmagorical31
- phantasmal20
- pharisaical20
- pharmaceutical30
- pharmacognostical35
- pharmacological33
- pharmacopeial28
- pharmacopoeial29
- pharyngeal21
- phaseal13
- phenobarbital26
- phenological25
- phenomenal21
- phenomenological33
- phenotypical27