This is the 6487th most frequent Chinese word.
收縮
"Contraction" or "shrinkage."
收縮 is used here to describe the physical shrinking or contracting of the air in the balloon.
氣球裡的空氣慢慢地收縮。
The air in the balloon slowly contracts.
收縮 in this sentence refers to the process of muscles tightening or contracting.
肌肉在運動後可能會收縮而感到疼痛。
Muscles may contract and feel sore after exercise.
收縮 is metaphorically used to describe the reduction or shrinkage of the company's market share.