The most common and most likely answer to this crossword clue is the 6 letter word DIMMED
I've seen this crossword clue in The Guardian
D
I
M
M
E
D
Buddy explains!
The straight part
We know that "became faint/became faint" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case became faint/became faint = dimmed.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 DIMMED mean?
DIMMED verb- To make something less bright.
- To become darker.
- To render dim, obscure, or dark; to make less bright or distinct
- To deprive of distinct vision; to hinder from seeing clearly, either by dazzling or clouding the eyes; to darken the senses or understanding of.