4 sentences

1. 她的腰部纤纤一握。

   tā de yāo​bù xiān​xiān yī wò.

   Her waist was slender enough to be held in one hand.

   Source: Dong Chinese Dictionary

2. 他用一条宽皮带围住腰部。

   tā yòng yī tiáo kuān pí​dài wéi​zhù yāo​bù.

   He wore a wide leather belt around his waist.

   Source: Dong Chinese Dictionary

3. 这件上衣腰部太紧了，需要放宽一点。

   zhè jiàn shàng​yī yāo​bù tài jǐn le, xū​yào fàng​kuān yī​diǎn.

   The waist of this top is too tight; it needs to be let out a bit.

   Source: Dong Chinese Dictionary

4. 医生建议他在坐着时挺直腰部，以减轻背部的压力。

   yī​shēng jiàn​yì tā zài zuò zhe shí tǐng​zhí yāo​bù, yǐ jiǎn​qīng bèi​bù de yā​lì.

   The doctor advised him to sit up straight to reduce the pressure on his back.

   Source: Dong Chinese Dictionary