The most common and most likely answer to this crossword clue is the 6 letter word OUNCES
I've seen this crossword clue in The Sunday Telegraph
O
U
N
C
E
S
More clues leading to the result OUNCES
- Cats — over fifty disposed of by relatives
- A little weight UNESCO's thrown about
- Betrays no hiding place for anything less than a pound
- Cats in the pound
- Youngster hides away from boozy dozens, spotted prowlers
- Measures ricochets blowing top
- Very upset about relative losing pound — or less than a pound?
- Measures springs without pressure
- Undomesticated cats in parts of pound
- These wild cats apparently weigh very little
Buddy explains!

The straight part
We know that "Undomesticated cats/parts of pound" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case undomesticated cats/parts of pound = ounces.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 OUNCES mean?
OUNCES noun- An avoirdupois ounce, weighing 1/16 of an avoirdupois pound, or 28.3495 grams.
- A troy ounce, weighing 1/12 of a troy pound, or 480 grains, or 31.1035 grams.
- A US fluid ounce, with a volume of 1/16 of a US pint, 1.8047 cubic inches or 29.5735 millilitres.
- A British imperial fluid ounce, with a volume of 1/20 of an imperial pint, 1.7339 cubic inches or 28.4131 millilitres.
- A little bit.
- A large wild feline, such as a lynx or cougar.
- Now specifically, the snow leopard, Uncia uncia.