/ ˌpɜːspəˈreɪʃn; NAmE ˌpɜːrs-/ noun [ U ]
1.
drops of liquid that form on your skin when you are hot
SYN sweat :
Beads of perspiration stood out on his forehead.
Her skin was damp with perspiration.
2.
the act of perspiring :
Perspiration cools the skin in hot weather.
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WORD ORIGIN
early 17th cent.: from French , from perspirer , from Latin perspirare , from per- through + spirare breathe.