Correct

吁吁

/ xūxū / 
Strokes

Definition

to pant/to gasp for breath

Example

As an Onomatope

pant; puff

1
Pá
爬
huàshān
华山
zhēn
真
jiào
叫
rén
人
qìchuǎnxūxū
气喘吁吁
  
。

Climbing Mount Huashan is a real breather.

2
Qìchuǎnxūxū
气喘吁吁

pant; puff hard/heavily; be out of puff/breath; be short of breath; be breathless