The digger has a name for it (7)
I believe the answer is:
mineral
'it' is the definition.
The definition suggests a singular noun which matches the answer.
'the digger has a name' is the wordplay.
'the digger' becomes 'miner' (I've seen this in another clue).
'has' is a charade indicator (letters next to each other).
'a name' becomes 'al' ().
'miner'+'al'='MINERAL'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for mineral that I've seen before include "Zinc or magnesium, say" , "Gypsum or magnesia, say" , "Substance that is (usually) inorganic" , "What drink is available in ground" , "Substance needed for health; ore" .)