Says a bone has been used as a meat substitute (4,5)
I believe the answer is:
soya beans
'been used as a meat substitute' is the definition.
I can't tell whether this definition defines the answer.
'says a bone' is the wordplay.
'says a bone' can be anagrammed to 'SOYA BEANS'.
However, I am unsure how the anagram is indicated.
'has' is the link.
Can you help me to learn more?
(Other definitions for soya beans that I've seen before include "Vegetable source of protein" , "Asian pulses used as a source of oil" .)