Pastry item (3)
(Other definitions for pie that I've seen before include "Slapstick missile" , "Pastry product" , "In the sky, it's an empty promise" , "In the sky, it's a hopeless idea" , "In the sky, this dish is impractical" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">pastry item</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for tart that I've seen before include "Somewhat sour like flat cake" , "sour type of pie" , "Sharp tasting- like kind of pie?" , "Sharp, acidic" , "See 10" .)