one's egg money
(butter and) egg money
old-fashioned Extra money earned by a farmer's wife by selling various things produced by the farm, such as (though not only) eggs and butter. My grandmother used all her egg money she'd been saving to help pay for my father's passage to America. I've been putting aside the butter and egg money each week to save up for a new dress.
one's (butter and) egg money
Fig. money that a farm woman earns. (Farm women would often sell butter and eggs for extra money that would be stashed away for an emergency.) Jane was saving her butter and egg money for a new TV. I've got my egg money. Let's go shopping.