13 letters
- subcommittees26
- subinhibitory25
- subliteracies21
- subliterature19
- subreptitious21
- subsatellites19
- substitutable22
- substitutions19
- suitabilities18
- summabilities24
- superactivity26
- superaddition20
- supercritical24
- superfluidity25
- superfluities22
- superhumanity26
- superiorities17
- supermajority31
- supermilitant22
- superposition21
- superstitions18
- superstitious18
- suppositional22
- suppositories20
- surreptitious18
- survivability28
- switchbacking34
- switchgrasses23
- sybaritically25
- syllabicities23
- synchronicity27
- taciturnities18
- tangibilities20
- temporalities20
- tenosynovitis21
- territorially17
- testabilities17
- tetrahedrites16
- theatricality21
- thyroiditises18
- titillatingly21
- tonsillitises16
- totalitarians15
- traditionally19
- traditionless16
- tranquilities25
- transliterate15
- transmittable21
- transmittance21
- transposition18
- transvestites18
- triangularity20
- triaxialities21
- triliteralism18
- tritheistical19
- ultracritical22
- ultramilitant20
- ultravirility22
- uncapitalized32
- uncompetitive28
- unconditional22
- unconditioned22
- underactivity25
- unfamiliarity24
- uninhabitable25
- uninhibitedly25
- unitarianisms19
- unknowability29
- unmitigatedly24
- unparasitized28
- unpunctuality27
- unreliability22
- unremittingly24
- unsociability24
- unsuitability22
- untraditional18
- unworkability28
- upgradability26
- variabilities21
- vascularities22
- vendibilities23
- verifiability26
- veritableness22
- versatilities18
- verticalities21
- violabilities22
- vitalizations28
- viticulturist23
- vitrification24
- vituperations22
- volcanicities25
- vulcanicities26
- vulnerability26
- washabilities22
- wearabilities20
- wettabilities20
- whipstitching29
- whitewashings26
- whithersoever24
- witenagemotes22
- withdrawnness24
- witlessnesses18
- wollastonites19
- workabilities24