Steady source of income for a dairy farmer? (4,3)
I believe the answer is:
cash cow
'steady source' is the definition.
'cash cow' can be an answer for 'source' (I have seen 'source of profit' mean 'cash cow' so perhaps 'source' could also mean 'cash cow'). I am not certain of the 'steady' bit.
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for cash cow that I've seen before include "Lucrative endeavour" , "producing high market share" , "Money-spinning business" , "Business making large profits" , "Something providing a steady income or profit" .)