15 letters
- photosensitized31
- photosensitizer30
- photosensitizes30
- photosynthesize34
- phototactically30
- phototelegraphy30
- phototoxicities30
- phototropically30
- phototypesetter25
- phrasemongering29
- phthalocyanines30
- physicochemical37
- physiographical33
- physiologically32
- physiopathology32
- physiotherapies27
- physiotherapist27
- phytochemically37
- phytoflagellate30
- phytogeographer31
- phytogeographic34
- phytopathogenic33
- phytoplanktonic35
- phytotoxicities32
- plethysmographs33
- plethysmography35
- polymorphically36
- prosopographies28
- protoporphyrins29
- pseudepigraphon31
- pseudomorphisms31
- psychobiography37
- psychophysicist35
- radioautographs24
- radioautography26
- radiotelegraphs24
- radiotelegraphy26
- radiotelephones23
- rechoreographed28
- rechromatograph30
- rephotographing30
- rhinencephalons29
- rhombencephalon34
- roentgenography28
- saprophytically32
- semipornography31
- sophisticatedly27
- sophistications24
- spectrographies28
- sporangiophores26
- superenciphered29
- superphenomenon30
- superphosphates29
- sycophantically33
- telegraphically30
- telephotography30
- topographically32
- typographically34
- ultrasonography27
- unchoreographed30
- underemphasized36
- underemphasizes35
- unsophisticated26
- xerographically36
- xeroradiography32
- zoogeographical37