use '?' for JOKER (blank)

From letters V, I, D, E, O, C, O, N, F, E, R, E, N, C, E  I made following words

15 letter words

videoconference[26]

14 letter words

overconfidence[25]

11 letter words

reconceived[19], reconvinced[19], noncoercive[18]

10 letter words

confidence[18], conference[17], reconceive[17], reconvince[17], reconfined[16], reconvened[16]

9 letter words

conceived[17], convinced[17], enfevered[16], conceiver[16], convincer[16], deference[15], inference[14], concerned[14], reconfine[14], reconvene[14], environed[13], endocrine[12]

8 letter words

creviced[16], conceive[15], convince[15], overfeed[15], coercive[15], overfond[15], confined[14], refenced[14], enforced[14], confider[14], evidence[14], convened[14], connived[14], deceiver[14], received[14], coderive[14], divorcee[14], revoiced[14], codriven[14], credence[13], conceder[13], conferee[13], corniced[13], confiner[13], overnice[13], convener[13], conniver[13], convenor[13], redefine[12], cicerone[12], croceine[12], foredone[12], coercion[12], veneered[12], innerved[12], overdone[12], recoined[11], reconned[11], condoner[11]

7 letter words

fevered[14], crevice[14], overfed[14], defence[13], confide[13], deforce[13], cornfed[13], deceive[13], evinced[13], devoice[13], enfever[13], covered[13], codrive[13], divorce[13], codrove[13], vocoder[13], ecocide[12], concede[12], confine[12], refence[12], coerced[12], enforce[12], coinfer[12], conifer[12], concord[12], convene[12], connive[12], receive[12], cervine[12], revoice[12], corvine[12], eccrine[11], definer[11], refined[11], cicoree[11], cornice[11], crocein[11], crocine[11], concern[11], fordone[11], codeine[10], condone[10], fennier[10], encoder[10], encored[10], inferno[10], crooned[10], innerve[10], nervine[10], environ[10], noncore[9], needier[8]

6 letter words

fenced[12], coifed[12], forced[12], device[12], voiced[12], fennec[11], fierce[11], fencer[11], confer[11], evince[11], novice[11], ovonic[11], define[10], finned[10], foined[10], foodie[10], feeder[10], reefed[10], refeed[10], defier[10], fender[10], finder[10], friend[10], redfin[10], refind[10], coerce[10], cicero[10], fonder[10], foredo[10], roofed[10], evened[10], vendee[10], devein[10], endive[10], envied[10], veined[10], nevoid[10], reeved[10], veered[10], edenic[9], encode[9], codein[9], coined[9], conned[9], cooeed[9], conoid[9], decree[9], recede[9], deicer[9], decern[9], cinder[9], ferine[9], refine[9], recode[9], corned[9], nordic[9], roofie[9], condor[9], cordon[9], venene[9], venine[9], eocene[8], conine[8], neocon[8], encore[8], coiner[8], orcein[8], recoin[8], conner[8], indene[7], donnee[7], neoned[7], needer[7], denier[7], nereid[7], reined[7], dinner[7], endrin[7], oreide[7], redone[7], dinero[7], ironed[7], oroide[7], indoor[7], ionone[6], ronion[6]