13 letters
- posttreatment20
- pralltrillers20
- preindustrial20
- prestructured22
- prestructures21
- pretreatments20
- protectresses19
- prototrophies21
- proventriculi26
- psychiatrists23
- psychometrics29
- psychometries26
- psychotropics29
- psychrometric29
- putrefactions24
- quattrocentos27
- reattributing20
- reattribution18
- recalcitrance24
- recalcitrancy26
- recalcitrants21
- recentrifuged24
- recentrifuges23
- reconcentrate21
- reconnoitring21
- reconstructed22
- reconstructor21
- redistributed19
- redistributes18
- redistricting20
- reflectometry25
- refractometry24
- registrations16
- reintroducing22
- remonstrances21
- remonstrantly21
- remonstrating20
- remonstration18
- remonstrative21
- remonstrators17
- reorchestrate18
- repatriations17
- respirometric22
- restrengthens19
- restrictively23
- restructuring21
- retransferred18
- retransformed21
- retranslating18
- retranslation16
- retransmitted18
- retrenchments23
- retributively24
- retroactively23
- retroactivity22
- retrocessions17
- retrodictions18
- retroflection21
- retroflexions25
- retrogressing18
- retrogression16
- retrogressive19
- retrospecting22
- retrospection20
- retrospective23
- retroversions18
- seismometries19
- selenocentric22
- sensitometric20
- septentrional19
- sequestrating26
- sequestration24
- slipstreaming23
- somatotrophin22
- somatotropins20
- spectrographs26
- spectrography28
- spectrometers22
- spectrometric25
- spectroscopes25
- spectroscopic28
- stoichiometry23
- straightaways22
- straightbreds21
- straightedges20
- straighteners18
- straightening21
- straightlaced22
- straitjackets29
- straitlacedly21
- strangenesses17
- strangleholds21
- strangulating21
- strangulation19
- strategically22
- stratigraphic23
- stratocracies19
- stratocumulus23
- stratospheres18
- stratospheric21
- stratovolcano22
- streakinesses18
- streetwalkers21
- streetwalking24
- strengtheners19
- strengthening22
- strenuosities15
- strenuousness17
- streptococcal26
- streptococcic28
- streptococcus26
- streptokinase21
- streptolysins20
- streptomycete24
- streptomycins25
- stridulations17
- strikebreaker24
- stringcourses20
- stringinesses17
- strobilations18
- stromatolites17
- stromatolitic20
- strontianites15
- strophanthins22
- structuralism22
- structuralist19
- structuralize28
- structuration19
- structureless19
- subcontracted25
- subcontractor24
- subcontraries21
- subdistricted22
- subindustries20
- substructural23
- substructures22
- subtreasuries18
- superpatriots20
- superstratums21
- superstrength22
- supersymmetry27
- symmetrically28
- sympatrically28
- tensiometries17
- terrestrially17
- tetrachloride20
- tetracyclines23
- tetradynamous21
- tetrafluoride19
- tetrahedrally20
- tetrahedrites16
- tetraploidies18
- tetrapyrroles19
- tetrodotoxins22
- theatricalism22
- theatricality21
- theatricalize28
- theocentrisms22
- thermometries21
- thermotropism24
- thigmotropism26
- thunderstrike22
- thunderstroke22
- thunderstruck26
- thyrotrophins23
- toastmistress16
- tracheophytes25
- tracheotomies21
- tractableness21
- tradescantias18
- traditionally19
- traditionless16
- tragicomedies22
- trailbreakers21
- trampolinings24
- trampolinists21
- tranquilities25
- tranquilizers34
- tranquilizing37
- tranquillized36
- tranquillizer35
- tranquillizes35
- transactinide19
- transactional19
- transaminases18
- transatlantic19
- transcendence23
- transcendency25
- transcriptase20
- transcription21
- transcultural21
- transductants20
- transductions20
- transfections21
- transferences21
- transferrable21
- transfiguring23
- transformable24
- transfusional20
- transgendered19