13 letters
- packinghouses29
- painstakingly27
- paperhangings27
- paralanguages23
- parametrizing31
- parfocalizing35
- participating25
- patronizingly32
- peacekeepings29
- penetratingly23
- perambulating27
- peregrinating22
- permanganates23
- perseverating23
- perseveringly26
- personalising21
- personalizing30
- pettifoggings26
- phagocytizing37
- phagocytosing28
- pharyngitides24
- phosphatizing35
- photoengraved26
- photoengraver25
- photoengraves25
- photographing28
- photoionizing31
- photoreducing26
- photostatting21
- phrasemakings28
- phrasemongers24
- playwrighting29
- pontificating26
- preannouncing26
- precancelling28
- precautioning24
- precertifying27
- precipitating25
- preconceiving30
- preconcerting26
- predominating24
- preformatting25
- preganglionic26
- premarketings26
- premeditating23
- premoistening23
- prenominating24
- preportioning23
- prepossessing22
- preprocessing25
- preprograming27
- prepurchasing28
- prequalifying35
- prescheduling27
- prescreenings23
- presentencing24
- presignifying27
- prespecifying30
- presweetening23
- pretensioning21
- pretermitting22
- prevaricating26
- prizefighting35
- processioning23
- proliferating23
- prolongations21
- proportioning23
- proselytising22
- proselytizing31
- protolanguage23
- prussianising21
- prussianizing30
- radiographing24
- radiolabeling22
- ratiocinating20
- rationalising18
- rationalizing27
- reaccrediting23
- reacquainting30
- reafforesting22
- reaggregating22
- rearrangement20
- reattributing20
- reauthorizing28
- recalculating25
- recalibrating23
- rechallenging26
- rechannelling25
- rechristening22
- reciprocating25
- recirculating24
- reclassifying25
- reconfiguring26
- reconnoitring21
- reconsidering21
- recriminating23
- rectangularly24
- recultivating25
- redetermining21
- rediscounting22
- rediscovering24
- redistricting20
- reduplicating25
- reemphasizing33
- reengagements22
- reengineering20
- reformulating24
- refrigerating21
- regionalizing29
- regurgitating21
- rehypnotizing33
- reidentifying23
- reincarnating21
- reinnervating22
- reinoculating22
- reinstituting18
- reintegrating19
- reintroducing22
- rekeyboarding26
- relandscaping25
- relinquishing30
- relubricating24
- remonstrating20
- rencountering22
- rendezvousing32
- renegotiating19
- renormalizing30
- reorientating17
- repositioning20
- reprivatizing32
- reproachingly27
- reprogramming27
- reregistering18
- resegregating20
- resensitizing26
- resocializing29
- resolidifying23
- restabilizing29
- restimulating21
- restrengthens19
- restructuring21
- resuscitating20
- retranslating18
- retrogressing18
- retrospecting22
- revaccinating27
- reverberating23
- revictualling26
- rockhoundings28
- romanticising23
- romanticizing32
- rubbernecking31
- saccharifying29
- safecrackings29
- sailboardings21
- salpingitises20
- sandpaintings22
- scandalmonger25
- scapegoatings24
- schismatizing33
- scintillating22
- sequestrating26
- sharecropping27
- sharpshooting23
- sheepherdings24
- sheepshearing23
- shipbuildings27
- shortchangers23
- shortchanging26
- sidesplitting21
- singularities18
- singularizing30
- skateboarding24
- skeletonising22
- skeletonizing31
- slaveholdings25
- slipstreaming23
- smallholdings25
- snowboardings24
- snowmobilings27
- sociolinguist21
- soliloquising28
- soliloquizing37
- somersaulting21
- songfulnesses22
- sonneteerings18
- soundproofing25
- sparkplugging32
- speedboatings23
- sportfishings24
- sportscasting22
- sportswriting22
- springinesses20
- standardising19
- standardizing28
- stepparenting23
- steppingstone23
- stickhandling28
- stockbrokings30
- stockjobbings38