The word A-line is commonly used to indicate fitting from the shoulders to the hips and then broadening to the hem, but it may also mean widening from the shoulders to the hem while disregarding the waist and hips.
So, an A-line Kurta has a normal fit at the shoulder and a smooth A shape cut as it falls. The rough pattern for the same is shown below.
It is the most popular style among Indian women since it combines both Western and traditional elements.