The most common and most likely answer to this crossword clue is the 6 letter word APHTHA
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More clues leading to the result APHTHA
Buddy explains!
The straight part
We know that "evidence of complaint" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case evidence of complaint = aphtha.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 APHTHA mean?
APHTHA noun- Candidiasis, oral thrush, thrush (fungal infection of the mucous membranes of the mouth caused by any species of yeast from the genus Candida)
- An oral ulcer, disregarding the cause.
- Foot-and-mouth disease