The 33-year-old model insists sexiness doesn't mean "wearing a push-up bra and red lipstick and high heels" because being attractive is something that comes from "inside."
In an interview with W magazine, she said: "We live in the 21st century and with everything that's going on in the world, people always ask me what it means to be sexy, and sexy is not about wearing a push-up bra and red lipstick and high heels.
"Every woman is sexy in her own way. It's something that comes from inside of you. You don't have to go out there and show it--though if you want to go out there and show it, it's totally fine. When you see a woman dressed in a suit and sneakers, I think she's sexy."
The Victoria's Secret star - who has 22-month-old daughter Lea De Seine with her partner Bradley Cooper - thinks sexiness is about being "classy and sophisticated" and has more to do with "character" than appearance.
She said: " It's about your character, how you move, how you talk--that's sexy to me. It's not about a push-up bra to your neck and you can't breathe. It's something more classy and sophisticated and modern."
The brunette beauty added feels at her sexiest when wearing comfortable underwear, and insisted that being secure with her body is what "makes [her] feel confident".
She said: "You don't want to be stuck in an uncomfortable bra with wire sticking into your skin. What makes me feel confident is feeling good in your own skin. Love your body, embrace your body. It's self-confidence."