The most common and most likely answer to this crossword clue is the 8 letter word CENSORED
I've seen this crossword clue in The Sunday Telegraph
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More clues leading to the result CENSORED
Buddy explains!
The straight part
We know that "Altered words" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case altered words = censored.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does CENSORED mean?
CENSORED verb- To review for, and if necessary to remove or suppress, content from books, films, correspondence, and other media which is regarded as objectionable (for example, obscene, likely to incite violence, or sensitive).
- Having had objectionable content removed.