What does the term "shankhini" refer to in the classification mentioned in "Rasamanjari"?

Physiognomic trait

Answer:  Physiognomic trait
In the context of "Rasamanjari," "shankhini" refers to a physiognomic trait.

Bhanu Datta, a Maithil Brahmin who lived in Bihar in the fourteenth century, composed another favourite text of artists, Rasamanjari, interpreted as the ‘Bouquet of Delight’. Written in Sanskrit, the text is a treatise on rasa and deals with the classification of heroes (nayakas) and heroines (nayikas) in accordance with their age — baal, taruna and praudha; physiognomic traits of appearance, such as padmini, chitrini, shankhini, hastini, etc., and emotional states, such as khandita, vasaksajja, abhisarika, utka, etc. Though Krishna is not mentioned in the text, painters have introduced him as the archetypal lover.