I love these kinda things:
Kick
Six letter words starting with N:naggednailednapkinnationnaturenectarnearlyneaterneatlyneededneedleneckednegatenervesnestednestleneuternibblenicelynickelniecesnightsnimbleninetynogginnipplenobodynoodlenormalnoticenotionnovelsnovicenozzlenudgednuggetnursesnumbernurishnuzzlenylons
Some 7 letter S words are:salvagesauntersausagesandingscatterscamperscratchscuffleseasicksectionselfishsendingserioussessionshapelyshiftedsharpenshattershackleshakingsharingshimmershowingshuttershovelsshortlyshowersshuttlesickbedsizzledskilledskatingslammerslimmersmudgedsnaggedsnarledsnowmansnowingsnorkelsolvingsoldierspatterspecialspoiledsputterstaffedstaggerstalkerstarvedstammerstapledstationstartlestiffenstoragestressedstretchstingerstringystrikesstumblestutterstylishsubjectsublimesuctionsugaredsummarysupportsupposeswaggersweatersweeperswelterswingerswimmersyringe
Alliteration
Six letter words starting with the letter "T"ThreatThreadTinkerTimingTakingTeamedToppedTriple
RoundRafterRunnerRinkRealRenderRottenRankRooster
gatheringgenerategenerousgeometrygemologygeneticsgesturesgiraffesgiganticgigglingglitterygloriousgluttonygutturalgorgeousgovernorgraduategracefulgratefulgraciousgridlockgrillinggrowlinggruelingguessinggymnasts
sablesaltysandysaladsharesharpshanksharkskimpskillskirtslimesliceslideslopescuffscorescarfscramsmallsmilesmokespadespanksparkspeckspendspellsinceswordsheetsheersheepsceneshearsheikshakeshellshallskunkstinkstankstunkstartstampshameshiftshineswarmstormstoopstoolstovestonestolesweetsweatswearswornstumpstungstuckstackstickstockstripsteamstealsteelswingstingsnakesnackswingsmartstrumstorestorksmock
alliteration
6 letter words starting and ending with N:napkinnationneuronnotion
A few examples of 3-letter words starting with the letter O are:owloweoaroatown
Some three letter words starting with "s" are:sacsadsagsapsatsawsayseaseesetsewsexsheshysinsipsirsitsixslysobsodsonsopsotsowsoyspaspystysuesumsun