Sentence:  Without reason, against prudence, and at a moment's notice, he fell in love with a frivolous, golden-haired girl who used to tear about Simla Mall on a high, rough waler, with a blue velvet jockey-cap crammed over her eyes. Her name was Venner—<WSD>Tillie</WSD> Venner—and she was delightful. 
Meaning of the word marked with <WSD> tags:  A diminutive of the female given name Matilda.