The most common and most likely answer to this crossword clue is the 9 letter word AGGRAVATE
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More clues leading to the result AGGRAVATE
- Put out sepulchre that's cut in stone
- Annoy Margo regularly by removing it from sink
- Try to animate Avatar egg
- Annoy crooked garage claiming tax
- Make worse government in Indian city with tax on energy
- Silver jar containing a vicar’s first incense
- Increase, in Agra, government value added tax on energy
- Unfinished tomb in stone compound
- Garage designed to accommodate tank in compound
- To make matters worse, Georgia left before Virginia, slipping into a series of heavy metal bars
Buddy explains!

The straight part
We know that "Increase" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case increase = aggravate.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 AGGRAVATE mean?
AGGRAVATE verb- To make (an offence) worse or more severe; to increase in offensiveness or heinousness.
- (by extension) To make worse; to exacerbate.
- To give extra weight or intensity to; to exaggerate, to magnify.
- To pile or heap (something heavy or onerous) on or upon someone.
- To exasperate; to provoke or irritate.