I came across the word gamine in Patty Jane's House of Curl by Lorna Landvik (I posted about the book here). I don't recall having seen it before.
The feminine form of gamin (French) originally meaning street urchin.
Gaining popularity, the word was later used more generally to describe mischievous young women, slim, boyish, possibly wide-eyed, teasing and unattainable.
"Attractively pert," The OED adds.
Picture a slim girl with a pixie cut.
A number of reference sites online cite gamine as HarperCollins' word of the year for 1899. My brief search did not find any substantive evidence of this.
Apparently Audrey Hepburn was the quintessential gamine.