HSK V7-9
Correct

异性

/ yìxìng /
Strokes

Definition

the opposite sex/of the opposite sex/heterosexual/different in nature

Example

As a Noun

opposite sex

1
Jiāo
xìng
异性
péngyou
朋友

make a friend of the other sex

2
Bèi
xìng
异性
yǐn
吸引

be attracted to the opposite sex

As an Adjective

different in nature

3
Tóngxìng
同性
diàn
电荷
xiāngchì
相斥
  
,
xìng
异性
diàn
电荷
xiāng
  

Like electric charges repel each other and unlike ones attract each other.