13 letters
- paraesthesias18
- parainfluenza32
- paralanguages23
- parallelogram24
- paralytically26
- paralyzations29
- paramagnetism25
- parameterized29
- parameterizes28
- parametrizing31
- paramountcies24
- paramyxovirus33
- paranormality23
- paraphernalia23
- paraphrasable25
- parasexuality27
- parasitically23
- parasiticidal21
- parasiticides20
- parasitologic22
- parasyntheses21
- parasynthesis21
- parasynthetic24
- parathormones22
- parenthesized29
- parenthesizes28
- parenthetical23
- parfocalities23
- parfocalizing35
- parkinsonisms25
- parliamentary23
- parochialisms25
- parthenocarpy27
- partibilities20
- participating25
- participation23
- participative26
- participators22
- participatory24
- participially26
- particleboard24
- particularise21
- particularism24
- particularist21
- particularity23
- particularize30
- partisanships22
- partitionists17
- patriarchates21
- pearlescences24
- peculiarities21
- pentobarbital24
- perpendicular26
- pharisaically25
- pharmacognosy29
- pharmacologic30
- pharmacopeial28
- pharmacopeias27
- pharmacopoeia27
- pharyngitides24
- phenobarbital26
- philharmonics28
- plasterboards21
- polarimetries20
- polarizations27
- polarographic27
- polycarbonate26
- postlapsarian21
- postsecondary23
- precautionary23
- preclearances24
- predepartures21
- predischarged25
- predischarges24
- preliminaries21
- preliminarily24
- premarketings26
- preparatively26
- preparatorily22
- prevaricating26
- prevarication24
- prevaricators23
- procarbazines32
- proprietaries19
- protonotaries17
- quadripartite27
- quarrelsomely30
- quarterbacked34
- quarterfinals28
- quartermaster26
- quarterstaffs29
- quarterstaves27
- quasiparticle30
- questionaries24
- quincentenary31
- rarefactional21
- reactionaries17
- reappearances23
- rearrangement20
- rearticulated19
- rearticulates18
- rebarbatively26
- rectangularly24
- rectilinearly21
- regardfulness22
- reincarnating21
- reincarnation19
- rekeyboarding26
- remilitarized27
- remilitarizes26
- repartitioned18
- repopularized31
- repopularizes30
- revolutionary22
- rudimentarily22
- saccharifying29
- saccharimeter24
- saccharometer24
- saccharomyces29
- sailboardings21
- sarcastically23
- sarcophaguses24
- sarsaparillas18
- scalariformly26
- scarification23
- schoolmarmish27
- scratchboards25
- secobarbitals23
- secondariness19
- secretaryship23
- sectarianisms20
- sectarianized27
- sectarianizes26
- semiaridities17
- semilegendary23
- semiparasites19
- semiparasitic22
- semisedentary20
- separableness21
- separationist17
- sexagenarians24
- sharecroppers24
- sharecropping27
- sharpshooters20
- sharpshooting23
- sheepshearers20
- sheepshearing23
- shuffleboards27
- singularities18
- singularizing30
- skateboarders21
- skateboarding24
- snowboardings24
- softheartedly22
- solarizations24
- southeastward20
- southwestward23
- sparkplugging32
- spectacularly27
- specularities21
- squirearchies28
- standardbreds20
- standardising19
- standardizing28
- starchinesses19
- stepparenting23
- stereoregular17
- stipendiaries18
- storyboarding22
- subcontraries21
- subdepartment25
- sublibrarians22
- submandibular27
- subparagraphs27
- subventionary25
- subversionary24
- summarization30
- supercarriers20
- superchargers24
- supercharging27
- superhardened22
- supernumerary24
- superstardoms21
- supplementary27
- suprarational19
- swarthinesses19
- sybaritically25
- synarthrodial20
- tearfulnesses19
- telemarketers21
- telemarketing24
- temerariously20
- temporariness20
- tenderhearted18
- tetartohedral17
- thenceforward26
- thermonuclear24
- thoroughfares23
- totalitarians15
- transparences21