Or search: posterity
2 Syllables: SU
3 Syllables: SUU
3 Syllables: USU
abetting, abstention, addressing, alleging, amending, amendment, arresting, ascendant, ascending, ascension, assembling, assenting, assessing, attempting, attendance, attendant, attending, attention, attesting, avenging, begetting, besetting, caressing, cementing, clandestine, commencement, commencing, commending, comparing, compelling, compendium, compressing, condemning, condensing, confessing, consenting, contending, contenting, contention, contentment, contesting, convention, declaring, declension, defendant, defending, dependant, dependence, dependent, depending, depressing, descendant, descending, despairing, detention, dimension, dispelling, dispensing, dissension, dissenting, distressing, endeavoring, entrenchments, excelling, exempting, exemption, expelling, expending, expressing, extending, extension, fermenting, forbearing, foretelling, forgetting, impairing, impelling, impending, impressing, indwelling, intending, intention, inventing, invention, investing, lamenting, Lieutenant, millennium, momentum, offending, oppressing, possessing, preparing, presenting, presentment, pretending, pretension, preventing, prevention, professing, progressing, propelling, rebelling, redemption, refreshing, regretting, remembering, remembrance, repairing, repelling, repentance, repentant, repenting, repressing, requesting, resemblance, resembling, resenting, resentment, resplendent, retention, retrenchment, suggesting, suppressing, suspending, suspension, transcendence, transcendent, transcending, transgressing, unbending, undressing, unending, unerring, unsettling, unsparing, upsetting
4 Syllables: UUSU
5 Syllables: UUUSU

Found 314 words across 5 groupings. Skipped 53 excess words of a similar stem.