==> language/english/spelling/operations.on.words/transposition.s <==
   longest reversal  DESSERTS,STRESSED (8)
   longest well-mixed transposal 
    CINEMATOGRAPHER, MEGACHIROPTERAN  (15)
   longest transposition list
    APERS, APRES, ASPER, PARES, PARSE, PEARS, PRASE, PRESA, RAPES, REAPS, SPARE,
    SPEAR (12)
    ANGRIEST, ANGRITES, ASTRINGE, GAIRTENS, GANISTER, GANTRIES, GRANITES,
    INGRATES, RANGIEST, TEARINGS  (10) [SATING(ER), SIGNATE(R), TANGIER(S) (3)]
    ANORETICS, ATROSCINE, CANOTIERS, CERTOSINA, CONARITES, CREATIONS, REACTIONS,
    TRICOSANE (8)

  transposition with deletion, insertion, or substitution 
   longest well-mixed transdeletion 
    SONOLUMINESCENCES, UNECONOMICALNESSES (17/18)
   longest word transdeletable to a single letter
    CONCENTRATIONS-CONSTERNATION-CONTORNIATES-TRANSECTION-
    STENTORIAN-TRANSIENT-ENTRAINS-NASTIER-ASTERN-TEARS-SATE-TEA-AT-A (14)
   longest Baltimore transdeletion (word transdeletable on every letter)
     IDOLATERS: DELATORS, SOTERIAL, DILATERS, ASTEROID,
    STOLIDER, SOREDIAL, DILATORS, DIASTOLE, TAILORED  (9)
   shortest word that cannot be transadded to another word  SYZYGY (6)
   longest well-mixed transubstitution 
    MICROELECTROPHORESIS, SPECTROCOLORIMETRIES (20)
****
Unless noted otherwise, all words occur in Webster's Third New International
Dictionary, Merriam-Webster, Springfield, MA, 1961.