The most common and most likely answer to this crossword clue is the 7 letter word ENHANCE
I've seen this crossword clue in The Times
E
N
H
A
N
C
E
More clues leading to the result ENHANCE
- French in luck after missing initial boost
- Chaps gamble — neither begins to improve
- Better in French clubs avoiding risk
- Improve hospital in Cornish town with no parking zone
- Deacon has hinted regularly about upgrade
- Increase in Parisian Chinese seen at church
- Improve luck, having lost head after being oddly lost
- Guys risk losing their heads to improve
- Better to spray henna on coarse skin
- Better prospect when nurse is about
Buddy explains!

The straight part
We know that "boost" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case boost = enhance.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 ENHANCE mean?
ENHANCE verb- To lift, raise up.
- To augment or make something greater.
- To improve something by adding features.
- To be raised up; to grow larger.
- (radiology) To take up contrast agent (for an organ, tissue, or lesion).