use '?' for JOKER (blank)

From letters G, R, E, E, N, S, I, C, K, N, E, S, S  I made following words

13 letter words

greensickness[20]

12 letter words

snickersnees[18]

11 letter words

snickersnee[17], genericness[14], sincereness[13]

10 letter words

screenings[13], nicenesses[12]

9 letter words

greensick[16], ringnecks[16], sickeners[15], reseeking[14], geekiness[14], regencies[12], screening[12], secerning[12], recessing[12], sceneries[11], engineers[10], energises[10], greenness[10], ingresses[10]

8 letter words

ringneck[15], neckings[15], sickener[14], snickers[14], sickness[14], kneesies[12], keenness[12], skinners[12], generics[11], incenses[10], niceness[10], ecesises[10], essences[10], recesses[10], engineer[9], energies[9], energise[9], greenies[9], reseeing[9], sneering[9], greisens[9], gneisses[9], egresses[9], eeriness[8], eserines[8]

7 letter words

necking[14], recking[14], neckers[13], nickers[13], snicker[13], sickees[13], sickens[13], keening[12], kneeing[12], geekier[12], reeking[12], kerning[12], seeking[12], skeeing[12], keeners[11], skinner[11], enskies[11], kineses[11], reseeks[11], seekers[11], sinkers[11], kissers[11], generic[10], censing[10], cringes[10], cessing[10], incense[9], sincere[9], essence[9], creeses[9], cerises[9], censers[9], screens[9], secerns[9], cresses[9], greenie[8], engines[8], reneges[8], greisen[8], ginners[8], geneses[8], genesis[8], seeings[8], signees[8], ensigns[8], sensing[8], ingress[8], resigns[8], signers[8], singers[8], eserine[7], serenes[7], seiners[7], sereins[7], serines[7], sinners[7], senseis[7], seeress[7], seisers[7]

6 letter words

necker[12], nicker[12], sickee[12], sicken[12], creeks[12], ickers[12], sicker[12], snecks[12], snicks[12], keener[10], reseek[10], seeker[10], kernes[10], inkers[10], reinks[10], sinker[10], skeens[10], skenes[10], skeins[10], eskers[10], kisser[10], krises[10], skiers[10], kisses[10], cering[9], cringe[9], nieces[8], creese[8], cerise[8], censer[8], screen[8], secern[8], ecesis[8], censes[8], scenes[8], recess[8], screes[8], crises[8], scries[8], cesses[8], engine[7], renege[7], ginner[7], genies[7], seeing[7], signee[7], ensign[7], genres[7], greens[7], reigns[7], renigs[7], resign[7], sering[7], signer[7], singer[7], egises[7], sieges[7], gneiss[7], singes[7], egress[7], serges[7], reseen[6], serene[6], nereis[6], seiner[6], serein[6], serine[6], inners[6], renins[6], sinner[6], seines[6], sensei[6], resees[6], seiser[6], series[6], sirees[6], sneers[6], resins[6], rinses[6], serins[6], sirens[6], seises[6], nesses[6], senses[6]

5 letter words

creek[11], icker[11], eking[10], greek[10], genic[8], niece[7], nicer[7], genie[6], genre[6], green[6], eerie[5]