Femme fatales in movies are best described as villainous female characters who "lure" men and have an ulterior motive. They are characterized by wearing loud makeup and beautiful attires.
Definition
"It's an archetype that appears throughout history in mythology, art, literature and became a principal character in the hard-boiled detective novels and classic film noir of the 20th C."
Earliest examples
One of the earliest examples is Barbara Stanwyck in 'Double Indemnity' (1941). Other Hollywood examples include Gene Tierney ('Leave Her to Heaven'), Ava Gardner ('The Killers').
Bollywood
Some of the most popular examplesare Bindu ('Kati Patang'), Tabu ('Andhadhun'), Kajol ('Gupt'), Urmila Matondkar ('Kaun'), Katrina Kaif ('Race'), and Priyanka Chopra ('7 Khoon Maaf').