0' (3 letters) The term '0-shaped' is a combination of two crossword solutions: 'OVAL' (4 letters) and '0' (3 letters). An OVAL is a shape that is symmetrical along its vertical axis, with two ends that are curved inwards. The number 0 is a numerical symbol that is used to represent the absence of any quantity or magnitude. Together, these two terms form the shape of an '0', which is a circle with a hole in the middle.