Custard pie is a type of dessert that is made with a pastry crust and filled with a custard-based filling. The crossword solutions for the term 'custard pie' are 'FLAN' and 'FLAW'. FLAN is a Spanish dessert that is similar to custard pie, but it is usually made with caramelized sugar on top. FLAW is an imperfection or defect in something, which could be used to describe a custard pie if it has an imperfection in its appearance or taste.