15 letters
- infrastructures24
- infundibuliform33
- infusiblenesses25
- ingeniousnesses21
- ingenuousnesses22
- inheritableness23
- inhomogeneities24
- inhospitalities22
- initializations27
- injudiciousness32
- injuriousnesses28
- innocuousnesses23
- inoffensiveness28
- inoperativeness24
- inopportuneness25
- inquisitiveness31
- inquisitorially30
- insatiabilities20
- insatiatenesses17
- inscrutableness25
- insensibilities21
- insensitiveness22
- insensitivities21
- inseparableness24
- insidiousnesses19
- insignificances29
- insignificantly29
- insociabilities23
- insolublenesses23
- inspirationally24
- instantaneities18
- instantaneously22
- institutionally22
- instructiveness25
- instructorships25
- instrumentalism25
- instrumentalist22
- instrumentality24
- instrumentation22
- insubordinately25
- insubordination23
- insufficiencies30
- insurrectionary23
- insurrectionist21
- intangibilities23
- integrabilities22
- integrationists19
- intellectualism26
- intellectualist23
- intellectuality25
- intellectualize32
- intelligentsias21
- intelligibility26
- intemperateness23
- intensification24
- intensivenesses22
- interanimations21
- interbehavioral26
- interchangeable28
- interchangeably30
- intercollegiate23
- intercommunions28
- intercomparison26
- interconnecting27
- interconnection25
- interconversion25
- interconverting27
- intercorrelated21
- intercorrelates20
- interculturally26
- interdependence26
- interdependency28
- interdiffusions25
- interdigitating22
- interdigitation20
- interdivisional23
- interelectrodes21
- interelectronic24
- interestingness20
- interferometers22
- interferometric25
- interfraternity22
- intergeneration20
- intergradations20
- interindividual25
- interinfluenced27
- interinfluences26
- interiorization26
- interlacustrine22
- interlineations19
- intermediations21
- intermittencies23
- intermodulation23
- internalization28
- internationally22
- internucleotide23
- interoperatives23
- interparoxysmal32
- interpellations22
- interpenetrated21
- interpenetrates20
- interperceptual27
- interpermeating25
- interpersonally24
- interphalangeal26
- interpopulation25
- interpretations20
- interprovincial28
- interrogational20
- interrogatively25
- interrogatories18
- interscholastic25
- interstratified20
- interstratifies19
- intersubjective36
- intertextuality27
- intertwinements24
- interuniversity24
- intervalometers24
- interventionism25
- interventionist22
- intervisibility26
- intervisitation21
- intolerableness22
- intracellularly26
- intracerebrally26
- intramuscularly28
- intransigeances23
- intransigeantly23
- intraperitoneal21
- intrapopulation25
- intrapreneurial22
- intravascularly28
- intricatenesses20
- introspectional24
- introspectively29
- intrusivenesses22
- intuitivenesses22
- intussuscepting27
- intussusception25
- intussusceptive28
- invariabilities24
- invectivenesses28
- inventivenesses26
- investigational24
- invidiousnesses23
- invincibilities28
- inviolabilities25
- inviolatenesses22
- invisiblenesses25
- involuntariness24
- invulnerability29
- ionospherically28
- irasciblenesses23
- irrationalistic20
- irrationalities17
- irreconcilables27
- irreformability27
- irrefragability26
- irreparableness23
- irrepealability25
- irresistibility21
- irreversibility25
- irrevocableness27
- irritablenesses20
- judiciousnesses31
- jurisprudential32
- juxtapositional37
- keratinizations30
- kindergarteners24
- kindheartedness25
- kinesthetically29
- kittenishnesses23
- kremlinologists27
- laboriousnesses21
- labyrinthodonts26
- lackadaisically31
- laryngectomized37
- latensification24
- lateralizations27
- latitudinarians20
- legislatorships24
- legitimizations31
- leisurelinesses19
- lepidopterology28
- leukaemogenesis27
- lexicalisations28
- lexicalizations37
- lexicographical37
- liberalizations30
- libertarianisms23
- lickerishnesses26
- lightfastnesses24
- lightsomenesses24
- lignocelluloses26
- lignocellulosic29
- lignosulfonates25
- limitlessnesses21
- literalizations27
- litigiousnesses20