The most common and most likely answer to this crossword clue is the 6 letter word FLUFFY
F
L
U
F
F
Y
Buddy explains!

The straight part
We know that "Light" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case light = fluffy.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 FLUFFY mean?
FLUFFY noun- Someone or something that has a fluffy texture.
- A person who is superficial, who lacks depth or seriousness.
- A babycino (frothy milk drink).
- Covered with fluff.
- Light; soft; airy.
- Warm and comforting.
- Not clearly defined or explained; fuzzy.
- Lightweight; superficial; lacking depth or seriousness.