Definition of lightly:
without good reason; "one cannot say such things lightly"
with few burdens; "experienced travellers travel light"
with little weight or force; "she kissed him lightly on the forehead"
indulging with temperance; "we eat lightly in the morning"
with indifference or without dejection; "he took it lightly"
in a small quantity or extent; "spread the margarine thinly over the meat"; "apply paint lightly"
to a slight degree; "her speech is only lightly accented"