truncate
Meaning: to shorten by cutting off
Usage: After winning the derby, the jockey truncated the long speech he had planned and thanked only his mom and his horse.
abridge
Meaning: to shorten
Usage: Moby-Dick is such a long book that even the abridged version is longer than most normal books.
efface
Meaning: to wipe out, obliterate, rub away
Usage: The rain effaced the chalk drawing from the sidewalk.
expunge
Meaning: to obliterate, eradicate
Usage: Fearful of an IRS investigation, Paul tried to expunge all incriminating evidence from his tax files.
abrogate
Meaning: to abolish, usually by authority
Usage: The Bill of Rights assures that the government cannot abrogate our right to a free press.
expurgate
Meaning: to remove offensive or incorrect parts, usually of a book
Usage: The editors expurgated the offensive passages from the textbook.