Sunil was buying tickets at the counter when suddenly he noticed a lady's purse lying on the floor.

One word substitute is Reticule.

Reticule: a woman's small handbag, typically having a drawstring and decorated with embroidery or beading.
Parasol: a light umbrella used to give shade from the sun.
Vestibule: an antechamber, hall, or lobby next to the outer door of a building.
Veil: a piece of fine material worn by women to protect or conceal the face.