The most common and most likely answer to this crossword clue is the 8 letter word RINGLETS
I've seen this crossword clue in The Guardian
R
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More clues leading to the result RINGLETS
Buddy explains!

The straight part
We know that "Butterflies/Butterflies" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case butterflies/butterflies = ringlets.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 RINGLETS mean?
RINGLETS noun- A small ring.
- A lock, tress.
- Any of various butterflies with small rings on the wings, in the tribe Satyrini of the family Nymphalidae, such as Aphantopus hyperantus.