a formal gesture, mainly done by girls or women by bending the knees or body, often with one foot in front of the other, as a greeting or to show respect or civility;
e.g. She dropped into a deep curtsy when she approached the throne.
(verb)
to make a formal gesture of greeting, respect, or civility, by bending one's knees or body, often placing one foot in front of the other;
e.g. You are expected to curtsy when in the presence of royalty.