The most common and most likely answer to this crossword clue is the 10 letter word ESCALATING
I've seen this crossword clue in The Times
E
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Buddy explains!

The straight part
We know that "Increasing" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case increasing = escalating.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 ESCALATING mean?
ESCALATING verb- To increase (something) in extent or intensity; to intensify or step up.
- In technical support, to transfer a customer, a problem, etc. to the next higher level of authority