HSK V6
Correct

背心

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Strokes

Definition

sleeveless garment (vest, waistcoat, singlet, tank top etc)

Example

As a Noun
waistcoat; vest; singlet
1
Yāróng
鸭绒
bèixīn
背心

down-padded waistcoat/vest

2
Mián
棉
bèixīn
背心

cotton-padded waistcoat/vest

3
Fángdàn
防弹
bèixīn
背心

bullet-proof vest