I rekon its about as much as half a bag of flour....!! sorry.... not sure!!! what a silly thing to put in a recipe!! Could it be anymore vague...!!! x
I thought it would be a 1/2 cup? Trust in google!!
When in doubt, call a grandmother.
Using an American recipe to make banana cupcakes (yumyum) and it says to use half a margarine stick but I have no idea how much that is.