The most common and most likely answer to this crossword clue is the 7 letter word INFLECT
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T
More clues leading to the result INFLECT
- Liberal blocking corrupt change
- Modulate and polllute?
- Inspire about fifty to make changes in speech
- Change tone of line to be used during blight
- Vary how to end line on city held by popular paper
- Bend in fine line twisting over court
- Change ending in film, oddly, with treatment from ‘One Flew Over the Cuckoo’s Nest’
- Change the ending of popular fellow’s talks with second half cut
- Decline to vary pitch?
Buddy explains!

The straight part
We know that "Vary how to end" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case vary how to end = inflect.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 INFLECT mean?
INFLECT verb- To cause to curve inwards.
- To change the tone or pitch of the voice when speaking or singing.
- (grammar) To vary the form of a word to express tense, gender, number, mood, etc.
- (grammar, of a word) To be varied in the form to express tense, gender, number, mood, etc.
- To influence in style.