Sentence:  This tactic didn't work, so several weeks later, in a variation on a theme, I reported to two girls on the playground "I'm a <WSD>tomgirl</WSD>," calculating that if tomboys exist, <WSD>tomgirls</WSD> must also, and I must be one. That didn't work either, ... 
Meaning of the word marked with <WSD> tags:  A boy who behaves in a typically girlish manner.