Baby in family beginning to eat a little dissolved solid (5,4)
I believe the answer is:
stock cube
'a little dissolved solid' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'baby in family beginning to eat' is the wordplay.
'baby' becomes 'cub' (cub can mean a baby).
'in' is an insertion indicator.
'family' becomes 'stock' ().
'beginning to' indicates taking the first letters.
The initial letter of 'eat' is 'e'.
'stock'+'e'='stocke'
'cub' inserted into 'stocke' is 'STOCK-CUBE'.
Can you help me to learn more?
(Other definitions for stock cube that I've seen before include "Ingredient of soup or casserole" , "Six-sided dehydrated block used in cooking" , "Culinary flavour enhancer" , "Six-faced soup ingredient" , "Meat or vegetable extract used in soups and stews" .)