Can someone answer this question which nags at me every time I read “chilled butter” in a recipe. Does it mean straight from the refrigerator, therefore rock hard, or left out to slightly soften but still cool? Thanks in advance…....

It means putting butter in the fridge for 15 to 30 minutes to become firm.  Some recipes need the butter to be firm and not melt as easily.  This is especially true for pie crust.  I hope that helps you.