12 letters
- inactivation21
- inauguration18
- incineration18
- incorruption21
- incrustation18
- indiscretion18
- infibulation22
- infiltration18
- inflammation24
- ingratiation16
- inhabitation19
- inosculation19
- insanitation15
- insemination18
- inspissation17
- installation16
- instauration15
- instillation16
- insufflation22
- insurrection18
- intellection19
- inteneration15
- interception20
- intercession17
- interdiction18
- interjection26
- intermission17
- interruption18
- intersection17
- intersession14
- interstation14
- intervention19
- intimidation18
- intoxication24
- introduction19
- introjection26
- intromission17
- introversion18
- invagination21
- invalidation20
- invigilation21
- invigoration20
- irresolution15
- jurisdiction27
- labanotation18
- laterization23
- latinization24
- legalization26
- legitimation19
- liquefaction30
- localization27
- malformation23
- malnutrition19
- malocclusion25
- malversation21
- manipulation22
- masturbation20
- maximization35
- melanization27
- memorization28
- menstruation18
- minimization29
- ministration17
- misdirection20
- miseducation21
- misquotation26
- mobilization29
- modification23
- monetization26
- moralization26
- motorization25
- multibillion23
- multimillion23
- nasalization24
- nazification29
- nebulization28
- nidification21
- nonadmission19
- noneducation20
- noninclusion21
- notarization23
- notification20
- novelization28
- obliteration17
- obnubilation22
- optimisation19
- optimization28
- organisation16
- organization25
- ossification19
- overexertion24
- overreaction20
- overtaxation24
- pacification25
- paralyzation28
- penalization27
- perpetration19
- perpetuation20
- perspiration19
- perturbation20
- petrifaction22
- pigmentation22
- placentation21
- polarization26
- postabortion19
- postelection20
- postposition19
- potentiation17
- preadmission20
- precognition22
- precondition21
- predigestion19
- predilection21
- preformation22
- preinduction22
- premigration21
- prerecession19
- prescription22
- preselection20
- presentation17
- preservation20
- proclamation23
- prolongation20
- promulgation23
- propitiation19
- proscription22
- prostitution17
- protestation16
- prothalamion22
- purification23
- putrefaction23
- quantitation24
- quantization33
- racemization28
- ramification22
- ratification19
- reactivation20
- reallocation18
- reannexation22
- reassumption20
- recollection21
- recommission22
- reconception23
- reconnection21
- reconversion21
- reconviction24
- recuperation20
- redecoration17
- rededication18
- redefinition18
- reescalation17
- reevaluation19
- refoundation19
- regeneration16
- registration15
- reimposition19
- reimpression19
- reinspection20
- rejuvenation28
- remotivation20
- remuneration18
- renaturation15
- renomination18
- renunciation19
- reoccupation23
- repatriation16
- repercussion20
- replantation18
- repopulation21
- repossession16
- reprehension19
- reproduction21
- reregulation17
- resubmission20
- resurrection17
- reticulation18
- retrocession16
- retrodiction17
- retroflexion24
- retroversion17
- revalidation19
- revegetation19
- robotization25
- romanization26
- salinization24
- sanitization23
- satisfaction19
- scatteration16
- segmentation19
- sexdecillion26
- slumpflation25
- solarization23
- solicitation17
- solifluction22
- sternutation15
- stridulation16
- strobilation17
- stupefaction23
- suberization26
- subscription23