The most common and most likely answer to this crossword clue is the 7 letter word QUICKER
I've seen this crossword clue in The Times
Q
U
I
C
K
E
R
Buddy explains!

The straight part
We know that "faster" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case faster = quicker.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 QUICKER mean?
QUICKER adjective- Moving with speed, rapidity or swiftness, or capable of doing so; rapid; fast.
- Occurring in a short time; happening or done rapidly.
- Lively, fast-thinking, witty, intelligent.
- Mentally agile, alert, perceptive.
- Of temper: easily aroused to anger; quick-tempered.
- Alive, living.
- Pregnant, especially at the stage where the foetus's movements can be felt; figuratively, alive with some emotion or feeling.
- Of water: flowing.
- Burning, flammable, fiery.
- Fresh; bracing; sharp; keen.
- (of a vein of ore) productive; not "dead" or barren