Jenner, 21, is on track to be the youngest self-made billionaire thanks to her lucrative Kylie Cosmetics business which is valued at $900 million.
But many took aim at Jenner’s inclusion on the list with Dictionary.com appearing to take a swipe by tweeting the definition of “self-made”.
The tweet read: “Self-made means having succeeded in life unaided.
“Used in a sentence: Forbes says that Kylie Jenner is a self-made woman.”
Kardashian hit back in defence of her sister’s success insisting she is “self-made” and that not one of her siblings have relied on their parents for financial backing.
"I really didn’t get it, because she is 'self-made' — we are all self-made,” she told Refinery29.
“What, because we came from a family that has had success?
"To me, that doesn’t really make sense. I know so many people like that who haven’t turned out to be as successful as Kylie. If anything, I've seen the complete opposite."
Kardashian, who also owns KKW beauty and a hugely successful mobile app and emoji, or ‘kimoji’ line, claimed she and her siblings work harder than anyone else she knows.
"Me, Kylie, not one [of the siblings] has ever depended on our parents for anything besides advice,” she said.
"That’s how I lived my life with my dad [Robert Kardashian]. He never gave me anything.
"We might have the opportunity, but I’ve seen it go the complete opposite way. Nobody works harder than my sisters and my mum."
Jenner recently welcomed her first child, daughter Stormi Webster, with US rapper boyfriend Travis Scott.