use '?' for JOKER (blank)

From letters R, E, T, R, O, P, E, R, I, T, O, N, E, A, L  I made following words

15 letter words

retroperitoneal[17]

12 letter words

interpolator[14]

11 letter words

reoperation[13], reportorial[13], interpolate[13], preliterate[13], teleprinter[13], interpreter[13], reinterpret[13], interrelate[11], reorientate[11]

10 letter words

peritoneal[12], terreplein[12], interloper[12], peroration[12], repertoire[12], terneplate[12], intertroop[12], toleration[10], torrential[10]

9 letter words

peritonea[11], interlope[11], repletion[11], terpineol[11], operation[11], interloop[11], tropeolin[11], reoperate[11], pretorial[11], pretorian[11], proration[11], portioner[11], reprinter[11], perorator[11], petiolate[11], leptotene[11], peltation[11], potential[11], penetrate[11], patienter[11], protonate[11], preterite[11], repattern[11], interpret[11], retrainee[9], arteriole[9], orienteer[9], elaterite[9], orientate[9], natrolite[9], tentorial[9], reiterate[9], literator[9], tolerator[9], retortion[9], retreater[9]

8 letter words

perineal[10], pelerine[10], peroneal[10], pelorian[10], leporine[10], repealer[10], pearlier[10], prerenal[10], rareripe[10], repairer[10], petaline[10], tapeline[10], antelope[10], antipole[10], optionee[10], nopalito[10], optional[10], pearlite[10], aperient[10], interlap[10], trapline[10], triplane[10], epilator[10], petiolar[10], atropine[10], petronel[10], terpinol[10], troopial[10], pliotron[10], repartee[10], repeater[10], rerepeat[10], palterer[10], prealter[10], paltrier[10], pretrial[10], repenter[10], pretrain[10], terrapin[10], perorate[10], priorate[10], portiere[10], portlier[10], operator[10], pronator[10], parterre[10], parroter[10], reporter[10], patentee[10], tinplate[10], toeplate[10], patootie[10], potation[10], triptane[10], operetta[10], teleport[10], plottier[10], patentor[10], entrepot[10], patterer[10], pretreat[10], preterit[10], prettier[10], prattler[10], potterer[10], portrait[10], nearlier[8], ornerier[8], lateener[8], elaterin[8], entailer[8], treenail[8], aerolite[8], oriental[8], relation[8], retailer[8], retainer[8], relearnt[8], retailor[8], loiterer[8], anterior[8], orienter[8], reorient[8], ratooner[8], etiolate[8], laterite[8], literate[8], nettlier[8], tolerate[8], tentoria[8], tenorite[8], tolerant[8], trotline[8], rotation[8], letterer[8], reletter[8], litterer[8], rattener[8], retirant[8], rottener[8], nitrator[8], retorter[8]

7 letter words

elapine[9], opaline[9], perinea[9], repanel[9], plainer[9], praline[9], parolee[9], peloria[9], pereion[9], pioneer[9], proline[9], loopier[9], polaron[9], pearler[9], replier[9], preener[9], repiner[9], ripener[9], peroral[9], preoral[9], pornier[9], parrier[9], epilate[9], pileate[9], pantile[9], penlite[9], alienee[7], aliener[7], aileron[7], alienor[7], eloiner[7], loonier[7], earlier[7], learier[7], leerier[7], learner[7], relearn[7], onerier[7], loriner[7], lineate[7], elation[7], toenail[7]