tomboy: [16] Tomboy originally denoted a ‘rude or boisterous boy’, but before the end of the 16th century it was being applied to a ‘girl who behaves like a boisterous boy’. Tom (the familiar form of Thomas) is presumably being used to denote ‘maleness’ (here ‘typical male aggressiveness’).
tomboy (n.)
1550s, "rude, boisterous boy," from Tom + boy; meaning "wild, romping girl, girl who acts like a spirited boy" is first recorded 1590s. It also could mean "strumpet, bold or immodest woman" (1570s). Compare tomrig "rude, wild girl." Related: Tomboyish.
例文
1. Mary has always been a tomboy .She likes hiking and horseback riding.
メアリーはずっと男らしく、ハイキングと乗馬が好きだった。
2.His daughter is a saucy tomboy .
彼の娘はいたずら小僧だ。
3. Tomboy is a girl and behaves like a boy.
男の子のような振る舞いをする女の子。
4.She is an ordinary woman who could dress like a tomboy .
彼女も野ガキのような格好をした普通の女の子だ。
5.Her role as a 14-year old tomboy earned her rave reviews.