The most common and most likely answer to this crossword clue is the 5 letter word LIBRA
I've seen this crossword clue in The Times
L
I
B
R
A
More clues leading to the result LIBRA
- Sign left by one supporter
- Sign in book store missing line
- Sign made by one supporter following Liverpool's first
- Sign we’ve lost track of reference collection
- Old party leader in retreat, a sign
- Sign bishop invested in currency once
- Sign left one bishop really angry, to start with
- Scales calibrated to some extent
- Sign from Willi Brandt
- What was tender of Italians welcoming British stars?
Buddy explains!

The straight part
We know that "Scales" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case scales = libra.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 LIBRA mean?
LIBRA noun- A Roman unit of weight equal to about 327 grams.
- Any of various units of weight in Spanish- and Portuguese-speaking countries approximately equal to 460 grams or a little more than a US or UK pound.
- Alternative spelling of libbra, an Italian unit of weight.