use '?' for JOKER (blank)

From letters N, E, R, V, E, L, E, S, S, N, E, S, S, E, S  I made following words

15 letter words

nervelessnesses[18]

13 letter words

nervelessness[16]

12 letter words

severenesses[15], serenenesses[12]

10 letter words

evennesses[13], severeness[13], sereneness[10]

9 letter words

elevenses[12], nerveless[12], senseless[9], seeresses[9]

8 letter words

evenness[11]

7 letter words

elevens[10], venenes[10], releves[10], eveners[10], veneers[10], sleeves[10], vessels[10], serenes[7], lessees[7], lessens[7], seeress[7]

6 letter words

eleven[9], venene[9], releve[9], evener[9], veneer[9], levees[9], sleeve[9], reeves[9], severe[9], elvers[9], levers[9], revels[9], nerves[9], selves[9], vessel[9], sevens[9], serves[9], severs[9], verses[9], reseen[6], serene[6], lessee[6], lenses[6], lessen[6], resees[6], lesser[6], sneers[6], nesses[6], senses[6]

5 letter words

levee[8], reeve[8], elver[8], lever[8], revel[8], nerve[8], never[8], elves[8], evens[8], neves[8], seven[8], serve[8], sever[8], veers[8], verse[8], lenes[5], lense[5], nenes[5], resee[5], leers[5], reels[5], ernes[5], sneer[5], leses[5], seels[5], esnes[5], sense[5], erses[5], seers[5], seres[5], esses[5]

4 letter words

even[7], neve[7], ever[7], veer[7], eves[7], vees[7], revs[7], nene[4], leer[4], reel[4], erne[4], eels[4], else[4], lees[4], seel[4], esne[4], seen[4], sene[4], lens[4], rees[4], seer[4], sere[4], erns[4], eses[4], sees[4], less[4], sels[4], ness[4], sers[4]

3 letter words

eve[6], vee[6], lev[6], rev[6], eel[3], lee[3], nee[3], ere[3], ree[3], ern[3], see[3], els[3], les[3], sel[3], ens[3], sen[3], ers[3], res[3], ser[3], ess[3]

2 letter words

el[2], en[2], ne[2], er[2], re[2], es[2]