From adventure + -ess.

• (British) IPA: /ədˈvɛntʃəɹɪs/

adventuress (plural adventuresses)

1. A female adventurer; a woman who seeks adventure.
2. A woman of doubtful reputation or suspected character who pursues personal advancement, especially by sexual means; a demirep.
   • 2002, Colin Jones, The Great Nation, Penguin, published 2003, page 337:

     The ingenious adventuress, who may have become Rohan's mistress, formed a plan to make her fortune out of the cardinal's passion for power and the queen's passion for gems.

3. A female varietist.
   • 2008, Shobba De, Superstar India: From Incredible to Unstoppable, pages 90–01:

     And even an iconic movie star like Amitabh Bachchan is not embarrassed to state he approves of actress Aishwarya because she is "homely and domesticated" (read: not a sexual adventuress).

• French: aventurière
• German: Abenteuerin, Abenteurerin
• Portuguese: aventureira
• Russian: авантюри́стка