A seductress is a woman who talks someone into having sex with her, usually by charm rather than by force. Same judging, story-like flavour as seducer, and even more old-fashioned. The ending -ess is the old way English marked “female,” as in actor / actress. Many people now just say seducer for any gender, or they avoid both words. In films you will still hear seductress for a woman written as dangerously attractive. Though actually, it is not a kind word: it often turns the woman into a type in a story — the one who tempts — rather than a person. Use it knowing it carries that old, moralising tone.