==> language/english/spelling/sets.of.words/word.torture.s <==
This problem was discussed in _Word Ways_ in 1974-5.  In August 1974,
Ralph Beaman, in an article titled "Word Torture", offered the word 
SHADES, from which one obtains HADES, SHADE; ADES, HADE, SHAD; DES, ADE,
HAD, SHA; ES, DE, AD, HA, SH; S, E, D, A, H.  All of these are words
given in Webster's Third.

Since that time, a serious search has been launched for a seven-letter
word.  The near misses so far are:
Date    Person           Word     Missing
Aug 74  Ralph Beaman     GAMINES  INES, GAMI, NES, INE
Nov 74  Dmitri Borgmann  ABASHED  INE, NES, ABASHE, BASHE, ASHE (all in OED)
May 75  David Robinson   GUNITES  GU, GUNIT (using Webster's Second)
May 75  David Robinson   ETAMINE  ETAMI, TAMI (using Webster's Second)
May 75  Ralph Beaman     MORALES  RAL (using Webster's Second)
Aug 75  Tom Pulliam      SHEAVES  EAV (using Webster's Second)

Webster's Second has been used for most of the attempts since it
contains so many more words than Webster's Third.  The seven-letter
plateau remains to be achieved.