15 letters
- segregationists20
- semiretirements22
- semiterrestrial19
- semitransparent23
- serendipitously24
- sporangiophores26
- spreadabilities23
- stereochemistry25
- stereoisomerism21
- stereologically25
- stereotaxically29
- stereotypically27
- strenuousnesses19
- streptobacillus27
- streptothricins24
- strikebreakings29
- subreptitiously26
- superbureaucrat27
- supercalendered26
- superefficiency34
- superelevations25
- superenciphered29
- supererogations22
- superstructures24
- suppressibility28
- suppressiveness27
- surreptitiously23
- technostructure26
- teleconferenced28
- teleconferences27
- thermoreceptors26
- thermoregulated25
- thermoregulates24
- thermoregulator24
- thermoremanence28
- toastmistresses18
- transparentized30
- transparentizes29
- transparentness21
- treacherousness22
- tremulousnesses22
- ultimogenitures24
- ultraprecisions24
- ultrastructures22
- unappreciations27
- unceremoniously28
- unchoreographed30
- uncomprehending33
- underemphasized36
- underemphasizes35
- underemployment31
- underestimating24
- underestimation22
- unprecedentedly29
- unprepossessing26
- unpretentiously25
- unrealistically25
- unreconstructed26
- unreliabilities22
- unrevolutionary26
- venturesomeness25
- videoconference31